00:00:07
NARRATOR:
It's one of the most magnificent
cities of the ancient world:
00:00:10
Petra.
00:00:12
Its monumental temple-like tombs
soar over 100 feet tall.
00:00:18
And these wonders of engineering
are not constructed;
00:00:22
they're carved
out of sandstone cliffs.
00:00:28
At its height, Petra was the
center of a vast trading network
00:00:31
in frankincense and myrrh
and home to over 30,000 people
00:00:36
in one of the most bone-dry
deserts on earth.
00:00:41
UELI BELLWALD:
It's not an appropriate location
for a city.
00:00:44
There is not even drinking water
down there.
00:00:46
NARRATOR:
How did an ancient people
00:00:49
supply enough water
for this vast city?
00:00:54
And how did they carve
these magnificent structures
00:00:57
so high up in these cliffs?
00:01:02
To find out, a geoscientist
teams up with stonemasons
00:01:06
to carve a Petra-style tomb.
00:01:09
TOM PARADISE:
We're looking at something
that hasn't been witnessed
00:01:11
for almost 2,000 years.
00:01:13
NARRATOR:
And archaeologists
and hydro-engineers
00:01:17
discover how a group of nomads
00:01:20
transformed this desert city
into an oasis,
00:01:24
the Las Vegas
of the ancient world.
00:01:26
LEIGH-ANN BEDAL:
It's really conspicuous
consumption
00:01:28
of this precious resource,
water,
00:01:30
in this desert environment.
00:01:33
NARRATOR:
Finally, after 2,000 years,
00:01:36
the secrets of Petra
are about to be revealed.
00:01:41
Up now on NOVA,
"Petra: Lost City of Stone."
00:02:10
NARRATOR:
It's one of the driest places
is providon Earth. following:
00:02:12
(camel grunting)
00:02:14
Yet concealed among the canyons
of this harsh desert
00:02:19
in the Kingdom of Jordan
is a magnificent ancient city:
00:02:24
Petra.
00:02:29
For over a thousand years,
its location remained hidden,
00:02:34
protected
by fortress-like cliffs
00:02:37
and Bedouin tribes
who fiercely guarded its secret.
00:02:43
Then, in 1812,
00:02:45
a Swiss adventurer
disguised as an Arab pilgrim
00:02:49
risks his life to search
for the legendary city.
00:02:53
Johann Ludwig Burckhardt
makes his way through the Siq,
00:02:57
a dramatic canyon rising
almost 600 feet
00:03:01
that twists and turns
for nearly a mile.
00:03:04
Near its end,
the canyon widens
00:03:08
to reveal a towering
temple-like facade.
00:03:18
It is called the Treasury,
or "Khazneh" in Arabic.
00:03:24
Built 2,000 years ago,
00:03:26
it is a masterpiece of design
and engineering.
00:03:30
Majestic columns rise
from the canyon floor,
00:03:35
topped by ornately carved
capitals.
00:03:38
Statues of mythological figures
adorn its facade.
00:03:46
A fanciful urn graces its roof.
00:03:49
And a towering doorway
leads inside
00:03:53
to a room with three chambers.
00:03:56
Here, there is no
elaborate carving,
00:04:00
just the simple, natural beauty
of the stone.
00:04:05
And then we back away
and we realize
00:04:07
not only is this building
unique and fantastic,
00:04:10
but it has been carved into
the sheer face of living rock.
00:04:15
NARRATOR:
The Treasury
is actually a sculpture
00:04:18
on a monumental scale.
00:04:20
At 80 feet wide
and 127 feet tall,
00:04:26
it is twice the height
of the Mt. Rushmore memorial.
00:04:32
As Burckhardt continues
through the canyon,
00:04:35
he discovers hundreds
00:04:36
of magnificently carved facades
everywhere,
00:04:40
many rivaling the grandeur
of Egypt, Greece, and Rome.
00:04:47
But there is more:
the ruins of an entire city.
00:04:53
A 6,000-seat theater carved
right out of the sandstone,
00:04:58
a main street lined with huge
temple-like structures,
00:05:05
and even more spectacular
monuments
00:05:09
carved higher in the mountains.
00:05:14
But Burckhardt's rediscovery
of the legendary city
00:05:17
sparks more questions
than answers.
00:05:21
Who built Petra, and why?
00:05:29
Burckhardt was inspired
by stories
00:05:31
of a mysterious desert tribe
00:05:33
who gained their wealth
trading spices and silks
00:05:36
among China, India,
Egypt, and Rome,
00:05:39
and then hid their treasures
of gold in the cliffs.
00:05:45
Greek and Roman sources
provide a name for these people:
00:05:49
the Nabataeans.
00:05:55
An account
from the 4th century BCE
00:05:58
describes the Nabataeans
as nomadic tent-dwellers.
00:06:04
But three centuries later,
another source describes them
00:06:07
as a sophisticated people
inhabiting a prosperous city.
00:06:14
Around the time of Jesus,
00:06:16
Nabataea is a thriving kingdom
surrounded by Egypt, Judea,
00:06:20
and the vast
North Arabian Desert.
00:06:25
How, in just a few centuries,
00:06:28
did a village of tents
become a wealthy kingdom?
00:06:32
And how,
in the middle of a desert,
00:06:36
did they build Petra?
00:06:43
Tom Paradise has spent
over three decades
00:06:46
trying to find out.
00:06:49
He is a geoscientist
00:06:50
who specializes in preserving
ancient structures.
00:06:54
Alongside the Treasury,
he sees strange square marks
00:06:59
that could be a clue
to how it was built.
00:07:01
Are these marks the remnants
00:07:04
of where an ancient scaffold
was anchored to the cliff face?
00:07:07
PARADISE:
For many years, people
considered these to be holds
00:07:12
for wooden scaffolding
that may have been used
00:07:14
for the actual carving.
00:07:17
NARRATOR:
But Paradise has doubts.
00:07:20
If these are scaffolding marks,
00:07:22
why did the Nabataeans
leave them here?
00:07:25
And why are they found
nowhere else in Petra?
00:07:29
Paradise believes
the real reason for the marks
00:07:32
may be tied to the fanciful name
00:07:35
given to this monument
centuries ago.
00:07:38
PARADISE:
This building is called
the Khazneh, it is the Treasury,
00:07:42
and so legend goes back
millennia
00:07:45
that this housed riches.
00:07:47
NARRATOR:
Because it is known
as the Treasury,
00:07:50
people have searched it
for treasure.
00:07:51
Bullet holes riddle the urn
at the top,
00:07:56
and these marks may be footholds
00:07:58
to climb up
and get a closer look.
00:08:01
We think maybe
those footholds were carved
00:08:04
for the purpose of raiding
the upper parts of the Khazneh
00:08:07
looking for the treasure.
00:08:10
NARRATOR:
But the urn holds no gold;
it's solid rock.
00:08:15
The only treasures here are
the magnificent sculptures.
00:08:22
Whatever the true purpose
of these marks,
00:08:24
Paradise is certain
they're not for scaffolding.
00:08:27
After all, in this desert,
wood is relatively scarce.
00:08:34
So how on earth could
the ancient Nabataeans
00:08:37
carve such a huge monument
so high up in the cliff face
00:08:41
without scaffolding?
00:08:44
Paradise has a bold plan
to find out.
00:08:49
That go all the way down
to the top...
00:08:54
NARRATOR:
Working with a team
of stonemasons,
00:08:56
they will try to carve
a Nabataean-style facade
00:08:59
for the first time
in 2,000 years.
00:09:01
PARADISE:
I may be sitting on the answer
to the age-old question
00:09:05
as to how were these facades
carved.
00:09:07
NARRATOR:
At the same time, archaeologists
and hydro-engineers
00:09:12
are investigating how the
Nabataeans could even survive
00:09:15
in this bone-dry environment.
00:09:17
BELLWALD:
The entire hydraulic
infrastructure was built,
00:09:20
as I think I may prove,
following one master plan.
00:09:24
NARRATOR:
Their groundbreaking discoveries
00:09:27
are revealing
the engineers of Petra
00:09:30
were not only masters of stone,
but also of water,
00:09:34
transforming a desert city
00:09:37
into the Las Vegas
of the ancient world.
00:09:42
Now, can scientists
finally uncover
00:09:45
how a nomadic tribe
built this city of stone,
00:09:49
and why Petra ultimately
vanished into legend?
00:10:00
("Indiana Jones" theme playing)
00:10:06
NARRATOR:
Most people
will recognize the Treasury
00:10:09
from the climactic scene
00:10:10
of Indiana Jones
and the Last Crusade,
00:10:13
where Harrison Ford
and Sean Connery
00:10:14
enter a secret temple
to discover the Holy Grail.
00:10:20
But despite the great
Hollywood story,
00:10:23
the Treasury and most
of Petra's iconic buildings
00:10:26
are not temples;
they're tombs.
00:10:33
The Nabataeans left
very little writing,
00:10:35
but on some of their facades
are inscriptions
00:10:39
in an Aramaic script,
the common language
00:10:42
of the Middle East
in the time of Jesus.
00:10:45
This one, on a facade called
Turkmeniya, reads in part,
00:10:50
"This tomb is sacred.
00:10:52
"Nothing of all that is inside
00:10:54
shall be changed
or removed forever."
00:10:58
Tomb raiders disregarded notices
like this,
00:11:01
so human remains and grave goods
rarely survive.
00:11:05
But body-sized niches
leave no doubt
00:11:08
these were burial chambers.
00:11:12
In all, the cliffs of Petra
hold over 800 tombs.
00:11:18
CHRISTOPHER TUTTLE:
The prominence
of these monuments
00:11:21
led many of the early explorers
to consider the possibility
00:11:25
that this might just be a city
of the dead, a necropolis.
00:11:28
But over the past 200 years,
00:11:30
all of the research
has actually shown
00:11:32
it was a city of the living
as well.
00:11:35
NARRATOR:
Chris Tuttle has been working
here for more than ten years.
00:11:39
Although less than two percent
of the site has been excavated,
00:11:42
archaeologists have mapped
and surveyed the area.
00:11:46
All in all,
ancient Petra was a metropolis
00:11:50
about the size
of the island of Manhattan.
00:11:53
There is a two-square-mile
downtown
00:11:56
where people lived, worked,
and prayed.
00:12:01
Suburbs housing more people
stretch to the north and south.
00:12:06
Based on these surveys, Tuttle
can estimate the population.
00:12:11
TUTTLE:
At its height,
we expect this city
00:12:13
housed somewhere between
20,000 or 30,000 people.
00:12:16
NARRATOR:
Yet unlike cultures that bury
their dead in isolated areas,
00:12:21
in Petra, tombs are everywhere.
00:12:26
Why did the Nabataeans carve
their tombs throughout the city?
00:12:30
And how did they do it?
00:12:34
Paradise hopes
his carving project
00:12:35
will provide some answers.
00:12:38
PARADISE:
Creating an experiment
in which we reconstruct a facade
00:12:43
will give us insight
into how the Nabataeans
00:12:46
carved these fantastic facades
2,000 years ago.
00:12:49
NARRATOR:
But Paradise can't carve
his facade here.
00:12:54
Petra is a protected
World Heritage site.
00:12:58
He must find a cliff face
00:13:00
with the right kind of sandstone
somewhere else.
00:13:07
His search takes him
a world away,
00:13:10
to Southern California.
00:13:12
NATHAN HUNT:
This looks like a promising
prospect.
00:13:14
NARRATOR:
While the ocean view
is a sharp contrast
00:13:17
to the Jordanian desert,
00:13:19
the sandstone is identical
to Petra's.
00:13:22
Paradise enlists stonemasons
Blake Rankin and Nathan Hunt.
00:13:28
With permission
from the landowner,
00:13:31
they search
for just the right rock.
00:13:34
Hunt is a classically trained
master carver
00:13:38
and architectural sculptor with
over 18 years of experience.
00:13:43
We're looking
for a fine-grained sandstone
00:13:46
which lends itself
to ornamental carving.
00:13:47
NARRATOR:
Sandstone is a soft rock
00:13:51
made of compressed layers
of sand and minerals.
00:13:55
RANKIN:
That looks like the type
of stone we're looking for.
00:13:56
Yeah, this is great.
00:13:58
It looks like it's going
to carve really well.
00:14:00
NARRATOR:
The team has found
the perfect rock and cliff face.
00:14:04
Now, they must find
the right tools for the job.
00:14:10
Back in Petra, Paradise
discovers a clue in the stone:
00:14:15
chisel marks
made from iron tools.
00:14:19
PARADISE:
The technologies used
with chisels in stonework
00:14:21
haven't changed in 2,000 years.
00:14:23
We use the same chisels,
00:14:25
and so they leave
the same marks.
00:14:28
NARRATOR:
By matching
modern day tool marks
00:14:32
with those found in Petra,
their adviser Tom Paradise
00:14:36
tells them exactly
which tools to use:
00:14:40
the claw chisel,
00:14:42
the flat chisel,
00:14:44
and the pointed chisel.
00:14:47
PARADISE:
The pointed chisel is used
for the coarser chiseling
00:14:50
that removes
large amounts of rock.
00:14:52
NARRATOR:
So the pointed chisel
00:14:56
is exactly what Hunt
and Rankin use to begin work.
00:14:59
RANKIN:
Yeah!
00:15:00
It feels good to be carving.
00:15:02
NARRATOR:
But their exuberance fades fast.
00:15:06
Carving by hand
is seriously slow.
00:15:09
HUNT:
There's no way
we can do it by hand.
00:15:12
NARRATOR:
A Greek source says
the Nabataeans had few slaves,
00:15:16
but they probably did have
00:15:18
plenty of skilled manpower
and time.
00:15:23
Hunt and Rankin have neither,
but they have power tools.
00:15:32
Even so, Rankin insists
they're not cheating.
00:15:36
RANKIN:
This is a chisel
very similar to one
00:15:37
that the Nabataeans
would have used.
00:15:39
The only difference is that
00:15:40
we've mechanized
the hammer process
00:15:43
so that we can move a lot
of stone really quickly.
00:15:49
NARRATOR:
The carvers have found
the right rock
00:15:51
and the right tools for the job.
00:15:56
As Hunt and Rankin
prepare the cliff face,
00:15:59
Paradise must decide
what exactly to carve.
00:16:03
What makes a Nabataean tomb
Nabataean?
00:16:07
Many of the facades in Petra
00:16:10
actually look like
they belong somewhere else.
00:16:14
At the Treasury, Paradise finds
statues, columns, and capitals
00:16:18
reminiscent of ancient Greece
and Rome.
00:16:23
And across Petra,
00:16:25
he finds architectural features
from other far-flung empires:
00:16:29
a step design associated
with Assyria and Mesopotamia,
00:16:34
elephant-headed capitals
evoking India,
00:16:38
even Egyptian obelisks.
00:16:45
But among the familiar
00:16:47
are designs Paradise has seen
nowhere else.
00:16:51
PARADISE:
There's a pediment at the top
that is split in the middle,
00:16:55
capped by a cone, a capital,
and an urn at the top.
00:17:00
This isn't Greek,
this isn't Roman.
00:17:02
NARRATOR:
This new design
is seamlessly mixed
00:17:05
with features
from far-off cultures.
00:17:09
PARADISE:
The architecture
is this synthesis.
00:17:12
And this begins to tell us
a story that is the real Petra.
00:17:15
NARRATOR:
What makes a Nabataean tomb
Nabataean
00:17:19
is the combining
of their own unique style
00:17:23
with designs from other empires.
00:17:25
But how did these people
in the middle of the desert
00:17:29
come into contact
with such faraway places?
00:17:35
Two words:
frankincense and myrrh.
00:17:43
Frankincense and myrrh
00:17:44
were must-have luxury items
in antiquity.
00:17:47
In the New Testament,
they are among the gifts
00:17:50
the Three Kings bring
to the baby Jesus.
00:17:54
Made from dried sap
from trees
00:17:56
in the southern Arabian
peninsula,
00:17:58
they were burned obsessively
in religious ceremonies
00:18:01
in Egypt, Greece, and Rome.
00:18:04
But to get that incense
to consumers
00:18:07
throhout the Mediterranean,
00:18:09
it first had to be transported
through the desert.
00:18:19
After centuries
of living as nomads,
00:18:21
the Nabataeans knew
every secret source of water.
00:18:27
If you wanted
to cross the desert
00:18:29
and make it out alive,
you had better have a Nabataean
00:18:33
leading the way.
00:18:36
(camel grunting)
00:18:38
Along the route,
they built outposts
00:18:40
to guard their goods
and extract a toll.
00:18:44
In a valley just over
the mountain from Petra,
00:18:47
Andrew Smith has excavated
this fort called Bir Madhkhur.
00:18:52
ANDREW SMITH:
There was definitely
a Nabataean presence here,
00:18:54
most likely related to the trade
that came out of Petra.
00:19:01
NARRATOR:
Among the artifacts he excavated
00:19:03
are dozens of tiny clay
perfume bottles.
00:19:08
The Nabataeans
were most likely processing
00:19:10
some of the raw frankincense,
00:19:11
and they would have bottled
and then packed them tightly
00:19:15
so that they weren't
going to break
00:19:17
and probably loaded them
on camels or even donkeys.
00:19:22
NARRATOR:
The Incense Road became
the lifeblood of the Nabataeans,
00:19:26
pulsing from Saudi Arabia
to the port of Gaza,
00:19:30
the gateway to Greece and Rome.
00:19:36
The financial reward
from this trade
00:19:39
catapults a desert tribe
into a powerful kingdom.
00:19:43
Nabataean towns and tombs
spring up
00:19:47
throughout the northwestern
Arabian peninsula.
00:19:53
By the first century,
the Roman writer Pliny
00:19:56
called the Nabataeans
"the richest race on earth."
00:20:03
Much of their wealth
00:20:05
went into building
their capital city, Petra.
00:20:13
Tom Paradise believes
00:20:15
the Nabataeans'
far flung trade connections
00:20:17
influenced
their domestic designs.
00:20:20
PARADISE:
Because Petra is a crossroads
for the region,
00:20:23
it makes sense that they would
adopt and adapt
00:20:26
different architectural styles
00:20:28
from a lot of their
trading partners.
00:20:29
NARRATOR:
But with all these
different styles,
00:20:33
what should Paradise pick
for his carving experiment?
00:20:38
PARADISE:
This sort of facade represents
00:20:40
more than 500 other facades
in Petra.
00:20:44
So this style really is the
archetype of the tomb facades.
00:20:49
NARRATOR:
To Paradise, this tomb
is typically Nabataean.
00:20:54
Although it appears plain,
00:20:56
it's a mash-up of different
architectural styles.
00:21:01
It has the remains
of a Greco-Roman doorway,
00:21:04
Nabataean capitals,
an Egyptian cornice,
00:21:08
and a design from Assyria
00:21:10
that may represent
a stairway to heaven,
00:21:12
called a crow step.
00:21:15
But when the carving team
00:21:17
transfers the design
to California,
00:21:19
it isn't wide enough
to fit the rock.
00:21:22
You never really know
how it's going to work
00:21:24
in the stone
until you get started.
00:21:26
We think it's going
to look a lot better
00:21:29
if we widen the facade.
00:21:30
NARRATOR:
But how will making the facade
wider affect the design?
00:21:35
Make each block of the crow step
seven by seven inch.
00:21:38
This would be the edge
of the crow steps.
00:21:40
RANKIN:
That would be great.
00:21:42
NARRATOR:
Grappling with this problem,
the team may shed light
00:21:44
on a mystery that has confounded
scholars for decades.
00:21:48
Why do Nabataean tbs,
while similar,
00:21:51
have unique variations?
00:21:54
PARADISE:
There is one motif
they modify a lot,
00:21:57
and that is the crow step.
00:22:00
Why the difference
we have never really understood.
00:22:01
NARRATOR:
Some of the tombs in Petra
have crow steps
00:22:05
that reach all the way down
to a narrow ledge
00:22:08
called the cornice.
00:22:10
Other crow steps meet
in the middle.
00:22:13
Some scholars have argued this
reflects an evolution in design.
00:22:19
But Paradise thinks they have
struck upon a practical reason.
00:22:25
As we make the facade wider,
it really requires us
00:22:29
to take the crow steps
all the way down to the cornice.
00:22:34
NARRATOR:
If the facade is wider,
the crow steps must break apart.
00:22:38
PARADISE:
Increasingly, we notice that
changes of the rock
00:22:42
actually caused changes
within the design elements.
00:22:46
I think we have to give
more credit to the rock
00:22:49
than we have in the past.
00:22:50
Just sort of roughly mark
nine inches on there.
00:22:53
NARRATOR:
By carving their own facade,
00:22:55
they discover a basic principle
of Petra:
00:22:59
the rock influences
what they carve
00:23:02
and where they carve it.
00:23:07
But why here?
00:23:09
Choosing to build their capital
in the middle of a rocky desert
00:23:13
poses another age old question:
00:23:17
how did the Nabataeans
get enough water
00:23:20
to support
such a magnificent city?
00:23:24
One clue is here,
in the city center,
00:23:27
at a structure
known as the Great Temple.
00:23:31
Its monumental stairway
leads to a large stone platform
00:23:36
surrounded by over
a hundred columns.
00:23:41
Holes in the courtyard show
00:23:44
there are channels running
underneath it.
00:23:47
It's running
under the floor.
00:23:48
SUE ALCOCK:
Oh, that'll do it.
00:23:49
NARRATOR:
Sue Alcock leads a team
00:23:51
from Brown University
to investigate.
00:23:54
ALCOCK:
If we could make all this
surface architecture go away,
00:23:58
you know,
just kind of magically
00:24:00
lift it up and look down,
I think we would see
00:24:02
quite a network of these
channels and canals.
00:24:04
NARRATOR:
She may be sho on magic,
00:24:08
but Alcock does have another way
to look below the surface:
00:24:11
a technology called GPR--
ground-penetrating radar.
00:24:18
TOMMY URBAN:
Excavation is inherently
destructive.
00:24:20
This is a way to get a look
at what's down there
00:24:24
in the same way you would go in
for an x-ray perhaps
00:24:25
before you went in
for a surgery.
00:24:27
NARRATOR:
The radar sends a high-frequency
radio wave into the ground.
00:24:32
When the wave passes through
different materials,
00:24:36
like from stone to soil,
00:24:38
part of the wave
is reflected back.
00:24:41
But the speed of the wave
changes
00:24:44
depending on the material:
00:24:47
slower for soil,
faster through air.
00:24:51
Detecting these changes
00:24:54
is how the GPR sees
where the channels are.
00:25:00
The team systematically
drags the radar
00:25:02
back and forth
across the courtyard.
00:25:05
URBAN:
There's some kind of a channel
right there.
00:25:07
ALCOCK:
Oh yeah, look at that.
00:25:09
NARRATOR:
Beneath the Great Temple
00:25:12
is a network of channels
that looks like plumbing.
00:25:16
Intriguingly, the channels seem
to extend beyond the courtyard.
00:25:22
ALCOCK:
When we look at Petra,
00:25:24
we often tend to think about
building by building,
00:25:26
and actually, I think
it was all tied together.
00:25:28
NARRATOR:
Alcock believes these channels
are evidence
00:25:32
of a massive city-wide
water system.
00:25:35
Petra was an urban center,
and it had urban water supply.
00:25:38
NARRATOR:
There's just one problem
with this theory.
00:25:43
Petra is in one of the driest
places on the planet.
00:25:48
If the Great Temple
00:25:50
is indeed the heart
of a vast engineering system
00:25:54
that supplied an entire city
with water,
00:25:56
where is all that water
coming from?
00:26:08
One possible source is still
used daily by locals.
00:26:12
It's called Ain Musa,
or the spring of Moses.
00:26:16
Allison Mickel
and Cecelia Feldman
00:26:19
of Brown University's
survey team
00:26:22
join hydro-engineer
Charles Ortloff to investigate.
00:26:25
CECELIA FELDMAN:
In Numbers 20:11,
00:26:27
it talks about
how the Israelites
00:26:29
were wandering in the desert.
00:26:31
And Moses strikes this rock
in anger, and water flows forth.
00:26:34
NARRATOR:
The story of Moses miraculously
bringing forth water
00:26:38
has been linked in legend
to this rock and spring.
00:26:41
But it would take
an engineering miracle
00:26:45
to get this water from Ain Musa
to Petra's city center--
00:26:49
it's five miles away.
00:26:52
In the Siq,
the entrance to Petra,
00:26:55
the team finds evidence
00:26:57
for how the water
may have been brought here.
00:27:06
Running along the side
of the path is a narrow channel
00:27:10
which has imprints of what were
once enclosed ceramic pipes.
00:27:14
CHARLES ORTLOFF:
If you look inside
of the channel,
00:27:19
you can see the actual imprints
of ceramic sections
00:27:22
that are roughly about a third
of a meter long.
00:27:26
NARRATOR:
At roughly a foot long,
00:27:28
it would require
tens of thousands of segments
00:27:31
to create a five-mile pipeline
from Ain Musa,
00:27:34
high in the mountains.
00:27:36
And every one of those joints
00:27:38
would have the potential
to spring a leak.
00:27:45
Could the Nabataeans
possibly have pulled off
00:27:48
such a feat
of hydro-engineering?
00:27:55
At California State University
in San Jose,
00:27:58
Charles Ortloff and graduate
student Shayan Mizrahosseini
00:28:02
are trying to figure that out
using this 26-foot tank.
00:28:10
Water is extremely precious
to the Nabataeans,
00:28:13
so ancient engineers
00:28:15
needed to design a pipeline
that would be free of leaks.
00:28:19
NARRATOR:
Their challenge, and Ortloff's,
00:28:22
is how to get water
to flow through a pipe
00:28:25
as quickly and efficiently
as possible.
00:28:28
The different angles
represent different choices.
00:28:31
NARRATOR:
One choice seems obvious:
00:28:33
make the slope of the pipe
steep.
00:28:39
Ortloff sets the slope
to six degrees
00:28:41
and turns on the water.
00:28:47
Things start out well.
00:28:49
The water is flowing fast.
00:28:52
But it fills the pipe
too quickly,
00:28:56
producing an area of turbulence
known as a hydraulic jump,
00:29:00
which causes the water flow
to slow down.
00:29:04
ORTLOFF:
This is the hydraulic jump,
right here.
00:29:07
NARRATOR:
But there's a bigger problem:
00:29:09
the pipe is now filled
with water,
00:29:14
raising the pressure.
00:29:17
In the ceramic pipelines,
00:29:18
that pressure could create leaks
at the joints.
00:29:25
ORTLOFF:
So that design,
where we have the steeper slope,
00:29:27
is not good.
00:29:29
SHAYAN MIZRAHOSSEINI:
Okay, closing all the valves.
00:29:31
ORTLOFF:
If you can put the brick
on the other side,
00:29:34
we're just going
to slide it over.
00:29:37
NARRATOR:
Ortloff adjusts the slope
of the pipe to four degrees.
00:29:40
A little more.
00:29:42
There we go.
00:29:44
Got it.
00:29:48
NARRATOR:
A small change in the slope,
just two degrees shallower,
00:29:52
has a big impact
on the speed of the water.
00:29:56
ORTLOFF:
The big surprise here is that
we have only changed the slope
00:29:59
by two degrees,
00:30:01
and yet we have a completely
different flow pattern.
00:30:05
NARRATOR:
The flow is fast.
00:30:08
And in this test, the pipe never
completely fills with water,
00:30:12
which would be good news
for Petra's plumbers.
00:30:16
ORTLOFF:
The entire flow has an exposed
air space above the surface,
00:30:21
and this will prevent leakage
in the system.
00:30:23
NARRATOR:
With the help
of modern day tools,
00:30:27
Ortloff has shown that
the best design
00:30:29
for delivering water fast
and leak-free
00:30:31
is a four-degree slope.
00:30:36
And when Ortloff
measures the angle
00:30:38
of the carved channel in Petra,
he makes a remarkable discovery.
00:30:43
ORTLOFF:
If we look at actual
field measurements,
00:30:45
we're able to see that
with their pipeline,
00:30:48
the ancient Nabataean engineers
00:30:50
had a slope of approximately
four degrees.
00:30:53
NARRATOR:
2,000 years ago,
00:30:56
Petra's engineers worked out
the perfect design
00:31:00
for their long-haul pipelines.
00:31:02
ORTLOFF:
They invented
scientific principles
00:31:05
that were only officially
discovered in the West
00:31:09
some 2,000 years later.
00:31:11
NARRATOR:
It is clear that the Nabataeans
were master hydraulic engineers.
00:31:23
But water is not the only scarce
resource in the desert.
00:31:27
Wood from local trees
was also in short supply.
00:31:31
So how could the Nabataeans
build their tombs
00:31:35
so high up in the cliff face
00:31:37
without using large
wooden scaffolding?
00:31:40
Paradise finds an important clue
in this unusual carving,
00:31:46
aptly called
"The Unfinished Tomb."
00:31:49
The top is finished.
00:31:51
The upper area of the capitals
remains somewhat crude
00:31:54
and still in progress.
00:31:56
But then below that,
nothing has been carved at all.
00:32:00
It's the natural sandstone face.
00:32:05
NARRATOR:
To Paradise, the progression
of finished at the top
00:32:08
and barely started below
can mean only one thing.
00:32:14
The Nabataeans started
from the top and carved down.
00:32:18
NARRATOR:
The unfinished tomb
shows that Nabataeans began
00:32:22
by sculpting the top layer
of the facade,
00:32:25
and then worked their way
down the cliff face.
00:32:31
Getting windy again.
00:32:33
Yep.
00:32:35
NARRATOR:
Back in California,
Paradise tells Hunt and Rankin
00:32:38
they must carve their facade
Nabataean style:
00:32:41
top down
and without scaffolding.
00:32:44
HUNT:
There's a lot
of challenges involved
00:32:46
in trying to figure out
how the Nabataeans
00:32:49
carved a piece like this.
00:32:51
I die like a Nabataean
is my worst fear.
00:32:53
(laughing)
00:32:54
Falling off the rock.
00:32:56
NARRATOR:
Up to now, they've been using
safety harnesses.
00:33:01
But the Nabataeans'
top-down approach
00:33:04
gives them an ingenious idea
for how to carve
00:33:07
without harnesses
or a large wooden scaffold.
00:33:10
RANKIN:
We've drilled
into the stone here
00:33:13
and placed a couple of pins
and then put a plank on top
00:33:17
and created a temporary
and movable ledge
00:33:22
that doesn't require
a lot of material.
00:33:24
NARRATOR:
They drive three pins
into the rock
00:33:28
and lay just a couple of planks
of wood across them,
00:33:32
forming a platform.
00:33:35
As their carving descends,
00:33:37
it erases the holes
they've made,
00:33:39
leaving no sign
of their platform.
00:33:41
By the time we get
to the bottom,
00:33:43
we've pretty much removed
all evidence of any plank.
00:33:46
NARRATOR:
The pin and plank solution
works perfectly.
00:33:51
It could explain
how the Nabataeans
00:33:53
were able to carve so high up
without scaffolding,
00:33:57
and why no evidence
for the technique can be found.
00:34:02
Halfway through the carving,
00:34:05
the team makes
another discovery.
00:34:07
RANKIN:
We can move a lot of stone
really quickly
00:34:09
with these chisels.
00:34:11
We've been moving a surprising
amount of stone every day.
00:34:15
NARRATOR:
A little carving creates
a lot of rubble.
00:34:21
I really cannot believe
that much carving
00:34:22
produced this much rubble.
00:34:26
NARRATOR:
The rubble has formed a ramp.
00:34:28
This means they don't need
their platform anymore.
00:34:31
Now they can just walk up
to the façade.
00:34:35
PARADISE:
When we see this much material
being produced from the carving,
00:34:38
we now realize that we create
ramps from this rubble
00:34:41
that gives you access to the
facade for the stone carvers.
00:34:44
NARRATOR:
Combining the clues
found in Petra
00:34:47
with the discoveries
in the carving project,
00:34:50
a new theory emerges
00:34:52
for how the Nabataeans
may have carved the Treasury.
00:34:58
They begin by climbing
to the top.
00:35:01
Here, they cut a narrow ledge
into the cliff face.
00:35:07
Using ancient drills,
they fix pins below the ledge
00:35:10
and lay planks across to provide
a platform for the carvers.
00:35:15
The first thing they carve
is the urn,
00:35:18
and the upper layer
of the monument.
00:35:21
They work their way down,
00:35:24
sculpting the split pediment
and the magnificent statues.
00:35:29
About halfway down, the debris
from the carving forms a ramp.
00:35:35
Now the carvers can walk up
to theacade
00:35:39
and continue carving
the elaborate capitals
00:35:41
and the handsome columns.
00:35:45
We don't know
of any other culture or society
00:35:48
using this kind
of engineering technique
00:35:50
for this scale of construction.
00:35:54
NARRATOR:
The top-down approach turns out
to be a brilliant innovation
00:35:58
for carving these tombs
in Petra's sandstone cliffs.
00:36:06
But carving is only part
of the Treasury's grandeur.
00:36:13
Its impressive location
commands the head of the canyon
00:36:17
and the entrance to the city.
00:36:22
Yet the same narrow canyon that
creates this dramatic reveal
00:36:28
can also be a death trap.
00:36:35
These amateur videos capture
a rare but deadly desert hazard:
00:36:39
flash floods.
00:36:42
Petra's average annual rainfall
of just a few inches
00:36:46
can hit all at once
00:36:48
and pour down this gorge
with lethal force.
00:36:51
Flash floods took the lives of
22 French tourists here in 1963,
00:36:58
and even today
could damage the Treasury.
00:37:01
Ueli Bellwald, a Swiss architect
and archaeologist,
00:37:08
has come to Petra to protect
both tourists and the Treasury.
00:37:11
He's searching for clues
to how the Nabataeans
00:37:16
held back the floods.
00:37:18
BELLWALD:
When they decided to carve
this facade into the cliff,
00:37:22
they had to do something against
flash floods in wintertime.
00:37:27
NARRATOR:
Next to the Treasury
is a narrow gorge.
00:37:31
Here, Bellwald finds huge blocks
mortared together
00:37:34
to form an ancient dam.
00:37:38
BELLWALD:
It's 2,000 years old
00:37:40
and still totally preserved.
00:37:42
NARRATOR:
But this one dam would not be
enough to protect thTreasury,
00:37:48
so Bellwald is on the hunt
for more dams.
00:37:51
While the landscape appears
to be plain rock,
00:37:56
to Bellwald,
it is packed with clues.
00:37:59
He notices different colors
on the canyon wall.
00:38:03
Above this line,
the stone is dark.
00:38:08
Below, it's lighter,
00:38:10
which Bellwald believes
is caused by mineral deposits
00:38:13
from water once stored here
in a reservoir.
00:38:19
Following this water line
brings him to an area
00:38:22
where two deep grooves have been
carved into the canyon walls.
00:38:26
The grooves show
where a dam once stood.
00:38:31
BELLWALD:
All of these dams
had to be anchored
00:38:34
into the cliffs on both sides
that they could easily withstand
00:38:37
the pressure
of the retained water.
00:38:44
NARRATOR:
Following these clues,
00:38:46
Bellwald has uncovered
an ancient Nabataean dam system.
00:38:52
The Nabataeans built five dams.
00:38:55
And to make those dams
even more effective,
00:38:59
they carved a channel
140 feet long and 16 feet deep
00:39:05
to reroute some of the water.
00:39:08
This created a large area
to store overflow
00:39:12
and reduce the force
of the water
00:39:15
before it reached the Treasury.
00:39:17
It's an engineering feat
00:39:20
almost as impressive
as the Treasury itself.
00:39:24
BELLWALD:
They realized that
if they divert the water,
00:39:28
they allow the water to spread
out to a much bigger surface.
00:39:32
And this reduced
its speed tremendously.
00:39:34
It worked perfectly.
00:39:38
NARRATOR:
So perfectly, Bellwald
can't improve on this design.
00:39:46
Today, a team is repairing
this ancient dam network
00:39:49
so it can once again protect
the Treasury.
00:39:53
BELLWALD:
If we want to keep the Treasury
for the future,
00:39:57
we have to protect it again
as 2,000 years before
00:40:01
from flash floods.
00:40:02
And that's exactly
what I'm doing.
00:40:04
NARRATOR:
Because the threat of floods
was so great,
00:40:08
Bellwald believes the Nabataeans
must have built the dam system
00:40:12
and the Treasury
at the same time.
00:40:16
In fact, scholars now believe
the grand tombs,
00:40:20
the city center,
and the water systems--
00:40:23
most of the ancient city
of Petra--
00:40:25
were built within 100 years
around the birth of Jesus.
00:40:30
BELLWALD:
The entire hydraulic
infrastructure of Petra
00:40:34
was built
following one master plan.
00:40:36
NARRATOR:
So just how much water
did that system provide?
00:40:44
Back in San Jose, Charles
Ortloff is figuring that out.
00:40:48
These are the main
supplies of water
00:40:50
from all of the cisterns,
all the dams.
00:40:53
NARRATOR:
Ortloff has mapped
every water feature
00:40:56
he and other archaeologists
have discovered:
00:40:59
eight springs
for fresh drinking water,
00:41:02
36 dams to protect the city
from flash floods,
00:41:07
over 100 cisterns and reservoirs
to collect and hold rainwater,
00:41:12
and 125 miles of pipeline
00:41:15
to connect many
of these features
00:41:18
into one integrated
water system.
00:41:21
From the map
and his flume experiments,
00:41:24
Ortloff can estimate the total
amount of water available
00:41:28
to Petra's 30,000 people.
00:41:30
If you sum up all of the water
from various sources,
00:41:34
that would lead to eight liters
per person per day.
00:41:39
NARRATOR:
Eight liters is about
two gallons.
00:41:43
In a world before showers
and washing machines,
00:41:46
that's more than enough water
to survive on.
00:41:50
In fact, new discoveries
reveal that the Nabataeans
00:41:53
had enough water to transform
Petra into a desert oasis.
00:42:02
Evidence of that water surplus
is being found
00:42:05
right next to the Great Temple,
in a large open terrace.
00:42:10
It was named by early explorers
as the Marketplace,
00:42:15
so when Leigh-Ann Bedal
began digging here in 1998,
00:42:18
that's what she expected.
00:42:21
LEIGH-ANN BEDAL:
Because it had been called
a marketplace,
00:42:23
I came in prepared
to excavate a market.
00:42:26
NARRATOR:
But as she began digging,
at eight feet deep,
00:42:30
she discovered
waterproof cement.
00:42:33
BEDAL:
So we knew that we had something
containing water,
00:42:35
something deep.
00:42:37
NARRATOR:
Her team excavated further
00:42:39
and discovered
a subterranean structure.
00:42:42
BEDAL:
We have the southwest
corner here,
00:42:44
and directly to the north
is the northwest corner.
00:42:48
NARRATOR:
Bedal located all four corners
00:42:51
to discover overall dimeions
of 140 by 80 feet,
00:42:57
nearly the size
of an Olympic swimming pool.
00:43:00
Then, in the middle,
00:43:02
she found evidence
of a stone platform
00:43:05
and surrounding
the sunken structure, channels,
00:43:09
likely used for irrigating
a lower terrace
00:43:12
where soil samples suggest
the area had been cultivated.
00:43:17
When she puzzles
the evidence together,
00:43:20
Bedal concludes the marketplace
00:43:22
was in fact
a huge ornamental pool complex
00:43:26
including an island pavilion
and a garden on a terrace below.
00:43:31
BEDAL:
If you could imagine below us
00:43:34
this large pool of water
and then a green garden
00:43:38
with date palm trees
and flowers.
00:43:40
This is something that is
for showing off.
00:43:44
NARRATOR:
Throughout the city center,
archaeologists are finding
00:43:49
other decorative water features
like fountains,
00:43:52
and a canal running beside
a colonnaded street.
00:43:58
It's really conspicuous
consumption
00:44:00
of this precious resource,
water,
00:44:01
in this desert environment.
00:44:03
NARRATOR:
Conspicuous consumption of water
in the middle of a desert?
00:44:09
It seems Petra resembled another
flashy desert destination.
00:44:19
BEDAL:
A great comparison is Las Vegas,
00:44:21
where you have
this very arid desert
00:44:25
surrounding this oasis city,
where everywhere you go,
00:44:29
you see the use of water,
fountains.
00:44:33
By diverting a precious resource
into a wealthy center,
00:44:38
it sends a message
to anybody who sees it
00:44:41
that it is a place
of wealth and power.
00:44:43
NARRATOR:
For ancient visitors,
00:44:46
after days of traveling on camel
through the hot, parched desert,
00:44:51
entering this oasis city must
have made a powerful impression.
00:44:56
Petra's luxurious pools
00:45:00
and internationally inspired
architecture
00:45:03
likely sparked the legends
that echoed through the ages.
00:45:14
Back iCalifornia,
00:45:15
after two months of carving
and nearly 2,000 years,
00:45:19
architecture of far-off lands
emerges from the rock.
00:45:25
PARADISE:
We've got Assyrian,
Egyptian, Greco-Roman,
00:45:27
but you put it together,
00:45:30
you stand back
and it's Nabataean.
00:45:32
And now it's a little bit
Californian.
00:45:34
That's right.
00:45:38
NARRATOR:
Whether the Nabataeans were
carving tombs for the dead
00:45:42
or water channels
for the living,
00:45:45
their mastery of stone
00:45:47
was the key to Petra's wealth
and beauty.
00:45:57
So why did
the Nabataean kingdom decline
00:46:00
and Petra largely disappear?
00:46:05
Across the city,
00:46:07
collapsed columns point
to a prime suspect:
00:46:10
ancient texts record
a huge earthquake in 363.
00:46:15
ALCOCK:
As a result, for a while,
00:46:17
when archeologists
came to Petra,
00:46:19
any time they saw something
like this, they would say,
00:46:21
"Ah, this fell down in 363."
00:46:23
NARRATOR:
But one catastrophic earthquake
00:46:26
does not provide the whole
picture of the city's decline.
00:46:31
At the Great Pl, the most
luxurious place in Petra,
00:46:35
there's evidence that hard times
hit the city even earlier.
00:46:40
BEDAL:
It may have been as early
as the second century,
00:46:42
because at that point,
00:46:44
we find a lot of animal bones
at the bottom of the pool,
00:46:47
so it seems to have been used
for trash.
00:46:49
NARRATOR:
Found in the great pool,
00:46:51
this layer of fallen rocks
dates to around the 363 quake.
00:46:56
But below that,
00:46:57
the layer of soil
containing the animal bones
00:47:00
indicates the pool filled in
at least 100 years before.
00:47:05
And there is evidence
of more destruction
00:47:08
100 years after the great quake,
00:47:11
which may have fatally weakened
the city's protective dams.
00:47:18
Large sections of Petra's
main street are missing pavers.
00:47:23
Tom Paradise believes
they were washed away
00:47:26
in a catastrophic flash flood.
00:47:29
PARADISE:
The floodwaters rushed down
through Petra's city center,
00:47:34
ripping up cobblestones.
00:47:36
This flood inundated the city
00:47:39
and may have marked the end
of Petra's golden age.
00:47:46
NARRATOR:
Ironically, the very water
that brought life to Petra
00:47:51
may also have contributed
to its demise.
00:48:04
Today, in the hills
of Southern California,
00:48:08
the carving team is bringing
a bit of Petra back to life.
00:48:13
The final flourish
00:48:14
will be a feature
not found in other cultures:
00:48:18
a Nabataean-style capital
00:48:20
with a simple knob
in its cter.
00:48:24
Normally,
there is a detail here.
00:48:26
Typically, there is a leaf
or a flower here.
00:48:30
You never really see it left
in this very abstract form.
00:48:35
It's quite beautiful
in its splicity.
00:48:39
NARRATOR:
Paradise believes the Nabataeans
00:48:42
choose this simple form
out of respect,
00:48:44
almost reverence,
for the sandstone.
00:48:48
PARADISE:
Their sense of the rock
as a living material
00:48:50
that had to be sort of caressed
and worked
00:48:56
was really as remarkable
as their engineering expertise.
00:48:59
NARRATOR:
And the sandstone itself
becomes a tool
00:49:02
to finish the surface
of the tomb.
00:49:05
HUNT:
I'm using the same stone
that we carved off the rock.
00:49:09
I'm just rubbing
the last little stages,
00:49:11
just kind of carefully
finishing off that last surface.
00:49:29
NARRATOR:
Stone is at the core
of Nabataean lives.
00:49:31
The very name for their city,
Petra,
00:49:35
comes from the Greek word
for rock.
00:49:38
PARADISE:
The Nabataean relationship
with their sandstone
00:49:40
was fundamental
to who they were.
00:49:44
They're born
in this valley of rock,
00:49:47
they live
in this valley of rock,
00:49:51
and then when they die, they are
buried in the rock itself.
00:49:56
These hewn tomb facades become
their final resting place.
00:50:15
NARRATOR:
Each year, over half a million
tourists retrace the steps
00:50:18
of the explorer
Johann Ludwig Burckhardt
00:50:21
and gaze up in awe
at the Treasury.
00:50:31
But in the two centuries
00:50:32
since Petra was re-opened
to the Western world,
00:50:35
its distinctive engineering
and culture
00:50:38
is proving equal to that
of any ancient civilization.
00:50:43
TUTTLE:
Petra is more than a city.
00:50:45
It was the seat of a kingdom,
00:50:47
a kingdom whose peace
and prosperity
00:50:48
was the envy
of the ancient world.
00:50:51
NARRATOR:
Cisterns, channels, dams,
even fountains and pools.
00:50:59
The Nabataean mastery of water
00:51:02
fueled their astonishing city
of stone.
00:51:06
ALCOCK:
The water features
are underpinning everything.
00:51:08
If the Nabataeans
00:51:09
couldn't control the water,
you wouldn't have a city here.
00:51:11
NARRATOR:
Over 2,000 years ago,
00:51:14
a desert tribe settled
among these forbidding cliffs
00:51:18
and transformed this hostile
landscape into an oasis.
00:51:24
PARADISE:
The Nabataeans learned how to
maximize these limited resources
00:51:27
to produce a society
and a culture
00:51:29
that thrived and prospered for
hundreds and hundreds of years.
00:51:33
NARRATOR:
Burckhardt came here
chasing legends of a city
00:51:38
lost in the sands of the desert.
00:51:41
A city with riches
from all over the known world,
00:51:45
buildings that rivaled Egypt
and Rome,
00:51:50
and fountains and pools
overflowing with water.
00:51:53
Today, it's clear
many of the legendary splendors
00:51:59
of the lost city of Petra
are true.
00:52:21
The story continues online,
00:52:22
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00:52:33
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00:52:43
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00:52:52
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00:53:05
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