♪ ♪ <i> NARRATOR: Lost civilizations.
Mysterious sunken cities.</i> <i> And legendary Atlantis itself.</i> <i> Vanished beneath the waves.</i> PATRICK: There is a
huge amount of unrecorded
human history beneath the ocean's surface that we don't
know very much about at all. <i> NARRATOR: Imagine if we
could empty the oceans,
letting the water drain away</i> <i> to reveal the secrets
of the sea floor.</i> <i> Now we can, using the latest
underwater technology.</i> <i> Piercing the deep oceans
and turning accurate
data into 3D images.</i> <i> Is this a huge
underwater temple carved by a
mysterious lost civilization?</i> <i> NARRATOR: Why are these
perfectly circular stones</i> <i> lying at the bottom of
a bay in the Aegean Sea?</i> SIMON: There are shapes
on the seabed that
just don't make sense. <i> NARRATOR: Are these just
rocks, or the remains
of an ancient city?</i> <i>JON (over radio): Parts of
this are just beginning to
be revealed for the first time.</i> <i> Wow.</i> <i> NARRATOR: And is the real
site of Atlantis finally
about to be revealed?</i> -People want to believe
in places like Atlantis. They want to believe
in other worlds. (waves crashing) <i> NARRATOR: Stories
of sunken cities have
fascinated for millennia.</i> <i> The most tantalizing
of all: Atlantis.</i> <i> First described by
ancient philosopher,
Plato, a dazzling civilization</i> <i> destroyed by the gods as
punishment for human pride.</i> -People connect to that story,
and it's because of this idea
of an ancient civilization, a utopia, that
we've evolved from. <i> NARRATOR: 2,000 years
later, the idea of Atlantis</i> <i> continues to fascinate
A-list archaeologists.</i> <i> And the producers
of B-list movies.</i> <i> MAN (over TV): Atlantis is the
story of those who, like today,</i> <i> would use the
marvels of science to
conquer and enslave.</i> <i> Atlantis, a world
that worships strange
gods of science,</i> <i> of science, a
science gone berserk.</i> -Plato would have
loved this okay? He would have
had a great time. He would have said, 'at
last, you know, people
are listening to me. People are taking
my story seriously.' And he would have
enjoyed this immensely. <i> NARRATOR: Using science,
not science fiction,
draining the oceans</i> <i> exposes new evidence
about Atlantis.</i> <i> And other stories of
great sunken cities,
around the world.</i> <i> As the waters recede
from around the remote
Japanese island of Yonaguni,</i> <i> a mysterious formation
begins to appear.</i> <i> Could it be the creation of
an advanced, ancient people?</i> <i> Yonaguni lies in
the East China Sea.</i> <i> The waters here are perilous.</i> <i> Schools of hammerhead
sharks patrol, amid
powerful currents.</i> <i> Typhoons frequently
batter the island.</i> <i> For divers, it's the
ultimate challenge.</i> <i> Kihachiro Aratake is one of
the pioneers of diving here.</i> KIHACHIRO: The water
was crystal clear. I felt as though I was
looking down from the
seabed from the sky. <i> NARRATOR: Searching for
a new dive site, he makes
a startling discovery.</i> -I saw a steps-like formation,
like terraced fields. I thought for a moment
it was similar to the
Machu Picchu ruins. So, I named the spot
the submarine ruins. <i> NARRATOR: It's an
extraordinary spectacle.</i> <i> The size of five
football fields.</i> <i> Smooth-sided walls rise up
to the summit, the height
of an eight-story building.</i> <i> Flights of stone steps
climb up from the base.</i> <i> And on every side, the
shapes and forms are
strikingly regular.</i> -It can't be formed naturally,
without human involvement. It couldn't be like that. <i> NARRATOR: So,
what could it be?</i> <i> It's impossible to investigate
the structure fully by diving.</i> <i> The only way is to conduct
a survey using the latest
scanning technology.</i> HIRONOBU: Although the shallow
waters around Yonaguni Island
are close to human habitation, we don't know much about them. It's an unknown frontier. <i> NARRATOR: Using sonar scans,
Hironobu Kan records a</i> <i> complete digital map
of the sea floor.</i> <i> Using this data,
it's possible, for
the very first time,</i> <i> to drain away the waters
and reveal what lies
beneath in exact detail.</i> <i> The summit of the
mysterious structure
begins to appear.</i> (waves crashing) <i> Water pours off its smooth
terraced layers, exposing
them once again to the sky.</i> <i> And with the monument
left high and dry, its
true scale becomes clear.</i> <i> Vast, imposing
and spectacular.</i> <i> The incredible discovery
attracts worldwide attention.</i> <i> Divers, journalists
and TV crews flock to
Yonaguni, all asking:</i> <i> what could this
mysterious structure be?</i> <i> And scientists come here too.</i> <i> Among them is Professor
Masaaki Kimura, one of
Japan's top marine geologists.</i> KIMURA: When I dived
underwater to explore it I
felt right away that it must be a man-made structure. <i> NARRATOR: He finds several
features that he believes
indicate human activity.</i> -Here, you'll see
something that looks like
the front gate of a castle. It's like a tunnel,
and you go through it. <i> NARRATOR: On the far side
of the tunnel, a road loops
around to a flight of steps.</i> <i> Watched over by two
mysterious stone objects.</i> -There are mound-like
bulges here and here,
and if you look at them, you'll find turtles with their
necks extended, on both sides. <i> NARRATOR: According to
ancient Japanese folklore,
the dragon god, Ryujin,</i> <i> lives in an underwater palace,
watched over by turtles.</i> <i> To Professor Kimura, this
indicates that the monument</i> <i> is so important
it needs guarding.</i> <i> And that's not all.</i> -If you go up this path
you get to this place. This portion is triangular. That's why it's called
the triangle pool. Since this is fairly
big and shallow as well,
you can relax in it. Also, the sea surface is
very close to it and it's
warm due to the sunlight. You feel chilly after
you come out of the
deeper area down there, and you can warm up here. <i> NARRATOR: But the monument's
most striking feature
is its wide, flat terraces,</i> <i> Large enough to support
thousands of people.</i> <i> Professor Kimura believes
the gateway, stairs,
turtles and terraces</i> <i> all point towards one purpose.</i> -Judging from its
shape, I think they
used it as a castle. <i> NARRATOR: But to prove his
theory, Professor Kimura
needs more:</i> <i> the artifacts of those
who once lived here.</i> <i> He scours the structure
looking for clues, and</i> <i> discovers what look
like primitive tools.</i> <i> Then, hidden behind one of
the great walls, the most
remarkable find of all.</i> -Look at this,
a symbol is inscribed
here and here's a hole. Probably, they hung
this article like this. And here's something
looking like a letter. Maybe it could be a kind
of a talisman to protect
people from evil. <i> NARRATOR: For Professor
Kimura, the case is closed.</i> <i> The artifacts and
the monument's regular shapes
prove that humans lived here,</i> <i> 8,000 years ago.</i> <i> After that, rising sea levels
claim the territory of this
lost race of master builders.</i> <i> But is that the real
story of Yonaguni?</i> <i> NARRATOR: Professor
Kimura believes that this
extraordinary structure</i> <i> off the coast of Japan is a
gigantic castle, built long
before the pyramids of Egypt</i> <i> by a mysterious
lost civilization.</i> <i> But is it?</i> <i>With the water drained away,
it's possible to scrutinize the
monument in forensic detail.</i> <i> The edges appear regular and
straight, as if made from
blocks carved by human hand.</i> <i> But closer examination
reveals something else.</i> <i> The surfaces are
smooth and unbroken.</i> <i> The monument is not assembled
from handmade blocks,</i> <i> but is in fact one
solid mass of rock.</i> HIRONOBU: The pyramid area
and the headland behind it
are connected with each other. The surface of the terrain
has a lot of grooves, so you
may think they are separate, but since they consist of
the identical stone, they
are originally connected. <i> NARRATOR: The basic
form of the monument
is clearly natural.</i> <i> But what about the gateway,
steps, turtles and pool?</i> <i> Could it be that an
ancient people carved
into this huge rock,</i> <i> transforming it into a
great castle or temple?</i> <i> Studying the headland on
shore provides the answer.</i> <i> The shapes here are
strikingly similar to
those found on the monument,</i> <i> and that's because
they were formed in
exactly the same way.</i> <i> Both are made of
sandstone which, when
subjected to stress,</i> <i>such as during
an earthquake, can
fracture along vertical faults,</i> <i> forming angular shapes
and what look like steps.</i> PATRICK: Put something like
that underwater, have the
water wash over the top of it and clear away all the debris,
and you've got very, very
fine step-like structures. But they're no more
human made than any other
structure down there. <i> NARRATOR: The lack of tool
marks is further confirmation.</i> <i> The forces which
shaped this remarkable
place are geological.</i> <i> But what of the artifacts?</i> <i> Perhaps the monument,
if not built by ancient
people, was inhabited by them.</i> <i> Walking these steps.</i> <i> Crowding these
natural terraces.</i> <i> But so far, no other objects
have been found, suggesting
that the talisman and tools</i> <i> were dropped from a boat
passing overhead, landing on
the monument simply by chance.</i> -The clear thing for Yonaguni
for me is there's no pottery, there's no evidence of
actual human occupation. There's not a single
wall from the site. There's nothing on it, that
indicates human activity. <i> NARRATOR: The Yonaguni
Monument is an extraordinary
natural formation,</i> <i> created by epic
geological forces.</i> <i> But its shapes
appear so regular
that many still believe</i> <i> it holds a secret,
ancient purpose.</i> JIM: You can take
that leap if you have an
imagination and say yes, this could be an ancient
city beneath the sea but
in the case of Yonaguni I'm in those ranks
that feel that it's not. It's geology. -We want to believe
that science doesn't
have all the answers. We want to believe innately
that there is something out
there that we can connect with spiritually and that hasn't
really been polluted by being the subject of
scientific discovery. <i> NARRATOR: And still
amongst the believers
is Professor Kimura.</i> <i> He remains convinced that the
monument was inhabited by his
ancestors and continues to</i> <i> search for evidence to
prove the doubters wrong.</i> <i> Beneath the oceans of
the world lie many more</i> <i> tantalizing traces of
possible lost civilizations.</i> <i> As the water continues
to drain away, in the
Eastern Mediterranean,</i> <i> astonishing structures emerge
in a quiet island harbor.</i> <i> Is this jumble of shaped
stones the architectural
debris of a once great city?</i> <i> Alikanas Bay, a tourist
hotspot on the island
of Zakynthos, Greece.</i> <i> Diver, Pavlos Voutos,
sets out to take some
underwater photos.</i> <i> NARRATOR: Pavlos swims
farther out into the bay
in search of clearer water.</i> <i> Then, out of the gloom,
he sees something that
will change his life.</i> <i> NARRATOR: The debris
stretches out for hundreds
of yards in all directions.</i> <i> The area is so large that
Pavlos is convinced he's found
the remains of an entire town.</i> <i> NARRATOR: The discovery sends
a bolt of electricity through
the world of archaeology.</i> <i> Professor Michael Stamatakis,
immediately travels to
Zakynthos to investigate.</i> <i> NARRATOR: Stamatakis recalls
seeing similar shapes on land,</i> <i> at the site of an
ancient settlement built
over 2,000 years ago.</i> <i> NARRATOR: If the same shapes
lie on the sea bed, they could
indicate an ancient settlement</i> <i> just offshore concealed
under the bay and forgotten
about for centuries.</i> <i> Comparing the images
is not enough.</i> <i> The only way to
reveal a complete
picture of the structures</i> <i> is a detailed
underwater survey.</i> <i> Simon Brown is an
expert in 3D modelling.</i> <i> But the task facing
him is immense.</i> SIMON: Right now
we're not quite sure
how big the area is. I've estimated it's about
16 acres, which will be more than double the
largest subject I've
ever covered to date. It's a weird place. There is definitely features
here that I have never
seen anywhere else before. They look out of place. But then I started to see
more regular shapes that
looked that cut stone. So my mind then starts
to think, is it... is it manmade? <i> NARRATOR: Can draining the
waters of the Mediterranean
provide the answer?</i> <i> NARRATOR: Simon Brown
is mapping mysterious</i> <i> underwater structures
discovered in a Greek bay.</i> <i> Could they be the remains
of an ancient town?</i> <i> He takes nearly 4,000 high
resolution photographs of the
sea floor tracking each with</i> <i> pinpoint accuracy through GPS.</i> <i> Using these images, it's now
possible to do something which
has never been done before:</i> <i> drain the waters of
Alikanas Bay and reveal,
for the first time ever,</i> <i> a 3D plan of the
entire sea floor.</i> <i> As the Mediterranean begins
to recede, a world is exposed</i> <i> that's been invisible
for thousands of years.</i> <i> First, the rocky shoreline
is left high and dry.</i> <i> Then, from the
dark depths, regular
shapes begin to appear,</i> <i> hidden amongst the rocks.</i> <i> Could they be the bases of
stone columns which together
once formed a grand colonnade?</i> <i> The use of colonnades is
a turning point in ancient
Greek architecture.</i> <i> Builders can now switch
from wood to stone, a
far stronger material,</i> <i> to create ever larger
temples to the gods.</i> <i> A colonnade in Alikanas Bay
would prove that an important,</i> <i> ancient settlement
once stood here.</i> <i> But some experts
remain skeptical.</i> PATRICK: There are structures
all over the world that mimic something that humans
may have created. Doesn't mean that
humans created them. <i> NARRATOR: With the water
drained away, it's now
possible to search the</i> <i> sea bed for evidence
of human occupation.</i> <i> Fragments of the pots
people cooked with.</i> <i> Charcoal from their fires.</i> <i> Tools for farming, and weapons
for defending their homes.</i> <i> Any objects made of
metal, clay or stone
should have survived.</i> <i> But there's nothing.</i> <i> Which means
these extraordinary
remains, whatever they are,</i> <i> are not the relics
of a lost town.</i> <i> So, what are they?</i> <i> NARRATOR: Further analysis
reveals the formations
are what geologists call</i> <i> 'concretions'.</i> <i> Solid blocks of
sedimentary rock formed by
powerful volcanic activity.</i> <i> Underwater vents
release methane from
deep within the Earth.</i> <i> Combining with
microbes and sediment,</i> <i> the methane causes regular
circular shapes to form.</i> <i> Far from being a
relic of ancient Greece,</i> <i> the structures here
pre-date human activities
by five million years!</i> <i> Despite all the evidence
against his theory,</i> <i> Pavlos Voutos remains
convinced that the fantastical</i> <i> landscape he discovered
was shaped by his ancestors.</i> <i> NARRATOR: Classical
civilizations dominate the</i> <i> Mediterranean for
over a thousand years.</i> <i> Today, all around
its coast, people tell
stories of sunken cities.</i> <i> As the waters around
Greece drain away further,</i> <i> an extraordinary underwater
vista is exposed.</i> <i> Could these patterns on the
sea floor be the remnants
of an ancient city?</i> <i> The village of Elafonisos
sits on a small island
just off the Greek coast.</i> <i> At first glance, an
ordinary fishing port.</i> <i> But in 1967, less than 100
yards out to sea, something
attracts the attention of a</i> <i> visiting maritime
archaeologist.</i> <i> Snorkeling in 13 feet
of water, Nicholas Fleming
catches a glimpse of</i> <i> regular shapes
on the sea floor.</i> <i> Then, exploring deeper,
he sees what he thinks is
evidence of human activity.</i> FLEMING: I looked at these
rows of stones, and I just
had no idea what it was, but I realized immediately
that it was manmade, that
we were looking at a large part of a town, and
I mean I just went crazy. <i> NARRATOR: Fleming is
convinced he has found
something special.</i> <i> But could these simply
be natural formations,
mimicking human structures,</i> <i> like the concretions
of nearby Alikanas Bay?</i> <i> The following year,
Fleming returns with
a team of surveyors</i> <i> to discover the truth.</i> <i> Using tape measures, they
document what they find.</i> <i> And the results
are astonishing.</i> <i> The site is strewn with
signs of human activity.</i> <i> Pots, storage vessels
and tools lie across a
huge area of the sea bed.</i> <i> There can be no doubt:
Fleming has discovered the
remains of an ancient town.</i> <i> It's named Pavlopetri
after a nearby island.</i> <i> But who built it, and when?</i> <i> These questions inspire a
generation of archaeologists.</i> JON: Well I've always
been interested in submerged
settlement, submerged towns, and I'd read about
Pavlopetri as a boy. And this idea of an intact,
prehistoric town underwater
just seemed you know incredibly romantic,
incredibly exciting. <i> NARRATOR: Henderson can now
fulfill a childhood dream
and explore this haunted</i> <i> underwater world for himself.</i> -Here we have a quern stone. -You can see it's
got a very concave,
concave surface there. That's for grinding grain or
whatever it was that you were
turning into you know flour. That's quite a clear artifact. Very nice. There is a huge amphora. One, amphora, two amphora,
three, four, five. This gives you an example of
what's coming out of the sand, what's eroding out of the sand. Look, there's the base of an
amphora, there's the amphora
shape there, it's on its side. There's another one next to
it and another one there. <i> NARRATOR: And further into
the bay, more evidence
of human life, and death.</i> -So, here's a cist grave.
Edge set slabs. A very small one.
Possibly for a baby. There are about 40
of these on the site. <i> NARRATOR: Diving gives
intriguing glimpses of</i> <i> objects lying
upon the sea bed.</i> <i> But it's impossible to
gain a complete picture.</i> <i> To do this, it must be mapped
using the latest in underwater
scanning technology.</i> (waves crashing) <i> Using this data, it's now
possible to drain away the
waters above Pavlopetri and</i> <i> bring sunlight back to
a forgotten world and
a true Sunken City.</i> <i> With the entire
bay drained away,
everything becomes clear.</i> <i> The lines are the
foundations of buildings,
laid out in clear streets.</i> <i> At the heart of the town is
a large open area, perhaps
an ancient market place.</i> <i> And nearby, the remnants
of a huge structure, perhaps
an important civic building.</i> <i> The remains cover 20
acres and the town could
have housed 4,000 people.</i> <i> A thriving, ancient
settlement once existed here.</i> <i> The next challenge is to
discover who built it.</i> <i> And when.</i> -We know how old the
occupation of the site is,
because we've got pottery. And pottery particularly
in this part of the
world is very well dated. What was really
exciting is we actually found
evicdence of pottery from the end of the Stone Age. So, we've actually got
occupation here from
about 5,500 years ago. And then we've got
every single bit of
pottery you would expect up until about 1100 BC. There's no gaps in that. So, the place seems to have
been continuously occupied
throughout the Bronze Age. <i>NARRATOR: Pavlopetri was
occupied for 2,400 years during</i> <i> a revolutionary period
of human development.</i> <i> At its peak in the bronze age,
around 1700BC, it looked like
this: a perfect example of the</i> <i> time when Europeans start
to live in stone-built towns
with regular laid out streets.</i> <i> But one question remains.</i> <i> Why did the builders of
this town choose this
particular location,</i> <i> in a remote part
of ancient Greece?</i> <i> Exploring the
drained landscape
around the ancient city</i> <i> reveals an all-important clue.</i> <i> At its edge, a huge sand bank
stretches out into the ocean.</i> <i> During the Bronze Age,
people don't build
ports out of stone.</i> <i> They bring ships up to the
shore and then beach them.</i> <i> And Pavlopetri's location
means it can exploit the trade
routes that boom during the</i> <i> Bronze Age right across
the Mediterranean.</i> <i> Evidence of early commercial
activity is everywhere.</i> -The interesting thing is
we've clearly got a lot
of material coming in. We found thousands
and thousands of shards of
very large storage vessels, which have been used for
storing olive oil, wine, that kind of thing and
generally anything. They were like the
containers of the day. <i> NARRATOR: And that's not all.</i> <i> Pavlopetri is also a
hub for manufactory.</i> -We've got a lot of
evidence for loom weights,
thousands of loom weights, way more than you would need
for domestic production so it
seems that maybe textiles were something that were being
produced on the site
and perhaps exported. <i> NARRATOR: Pavlopetri is an
extraordinary, bustling,
vibrant port city.</i> <i> And an important
center of trade.</i> <i> So how did such an advanced
metropolis meet its end?</i> <i> NARRATOR: An ancient,
submerged city off
the coast of Greece.</i> <i> How it came to lie on the
sea floor is a mystery.</i> JON: One of the interesting
things about Pavlopetri and
its submergence is that there are no historical
references to it at all. It sunk under the waves
and then it was out
of sight, out of mind. And there's certainly no
classical sources that
refer to its sinking. And there's nothing until
it's discovery really
in the 20th century. <i> NARRATOR: Scanning
the drained bay could reveal
what happened to Pavlopetri.</i> <i> At the edge of the town,
it's possible to make out
three mysterious lines.</i> <i> These are strips of beach
rock, formed by the action
of sunlight on salt water.</i> <i> They form only
near the shoreline.</i> <i> It can mean only one thing:
earthquakes caused this land
to subside into the sea.</i> -So, there was a big
earthquake, perhaps part of
the remains went under the water, part of them are
still surviving, then there
was another earthquake it was pushed under then there was
a third, and it was gone. <i> NARRATOR: Pavlopetri is one
of the most important Bronze
age sites in the world,</i> <i> and the oldest submerged
town ever discovered.</i> <i> But it's not alone.</i> -A lot of the major finds in
the next couple of decades are
going to come from the sea. I think we have the
potential to rewrite what
we know about human history. <i> NARRATOR: Pavlopetri is an
extraordinary find, but it is
not the legendary Atlantis.</i> <i> Various locations for
Plato's dazzling city
have been proposed,</i> <i> around the world.</i> <i> But most academic
investigations point to one
place: the Mediterranean.</i> <i> As its waters continue
to drain away,
at its western end,</i> <i> new and tantalizing
evidence is revealed.</i> <i> Could archaeologists
finally have found the site
of Plato's famous lost city?</i> <i> Marc Gutscher
is a geophysicist, long
fascinated by Plato's story.</i> MARC: I do think that
becoming interested in
Atlantis can be almost, like a bug or an infection
or like gambling. I think one can
become obsessed. <i> NARRATOR: Plato wrote about
Atlantis in 360BC, describing
an advanced metropolis</i> <i> 9,000 years before his own
time, lost beneath the waves
in a cataclysmic event.</i> <i> Marc Gutscher has analyzed
Plato's texts, searching
for clues to its location.</i> -'This power came forth out
of the Atlantic Ocean from an
island situated in front of the straits which
are by you called the
Pillars of Heracles.' <i> NARRATOR: The Pillars of
Heracles is the name given by
Plato to the maritime boundary</i> <i> of the ancient Greek world.</i> <i> Many locations have
been suggested.</i> <i> But Marc believes he
has the answer: The
Straits of Gibraltar.</i> -So here at Cape Spartel we're
at the northern edge of the
Moroccan Atlantic coast and just at the entrance to
the Straits of Gibraltar. About 10 to 15 kilometers
off to the north west
there's a submerged bank. Some people have suggested
that it might have been
inhabited and it might have formed the origin of
the Atlantis legend. <i> NARRATOR: Today, this area
sits under the second busiest
shipping route in the world,</i> <i> a difficult place for
sub-sea investigation.</i> <i> During a project to study
rising sea levels here,
Marc gets his chance.</i> <i> Using a remotely operated
vehicle or ROV, he sets
out to map the sea floor.</i> (waves crashing) <i> It's challenging work.</i> -It was very difficult,
both the towing of the
camera was difficult, keeping the ship in place
was difficult, and especially
trying to keep the ROV in place was really,
really difficult. <i> NARRATOR: Finally, Marc
gets the sonar scanning
data that he needs.</i> <i> Now, combining
this information with the
latest computer graphics,</i> <i> it's possible to drain away
the sea water from between the
ancient pillars of Heracles,</i> <i> and attempt to solve one of
the greatest archaeological
mysteries of all time...</i> <i> Soon, rocks begin
to emerge, and the</i> <i> unmistakable outline of an
island gradually appears.</i> <i> Is this the site of
Atlantis, exposed for the
first time in 11,000 years?</i> <i> Once again, important clues
lie in Plato's own writing.</i> -Plato says that the city, and
all of its war-like men, were
destroyed in one day and night of terrible misfortune,
caused by strong
earthquakes and floods. <i> NARRATOR: The island revealed
by draining the ocean,
sits on a subduction zone,</i> <i> a boundary between the huge
tectonic plates that make
up the Earth's surface.</i> <i> The exact point where the
biggest earthquakes strike.</i> <i> A series of powerful
earthquakes and tsunamis could
have obliterated Atlantis and</i> <i> sent the island
on which it rests down
into the ocean depths.</i> -You could imagine that during
great earthquakes there might
have been some subsidence, so if we were to take into
account maybe 20 or 30 meters
of subsidence due to those earthquakes, there might
have been a somewhat
larger island there. <i> NARRATOR: The geology
supports Plato's account of
the destruction of Atlantis.</i> <i> But one other vital piece
of evidence is still needed.</i> <i> NARRATOR: Draining
the ocean has revealed
a mysterious island</i> <i> exactly where Plato
said Atlantis would be.</i> <i> But one other piece of
evidence must be present for
it actually to be Atlantis:</i> <i> The remains of substantial
man-made structures.</i> <i> Using the drained landscape,
it's possible to study
the island's surface</i> <i> in extraordinary
three-dimensional detail.</i> <i> Searching carefully for
the remains of walls,
temples, bridges,</i> <i> and anything constructed
by human hands.</i> <i> But there are none.</i> <i> Nowhere on this mysterious
island are there any lines or
geometric shapes which would</i> <i> indicate the presence of
a great, ancient city.</i> MARC: Atlantis did not exist
in the tiny island of Spartel. If it did exist traces of
it have not been found. <i> NARRATOR: However, the
story of this submerged
island is not over yet.</i> <i> There may be no trace of
a city built out of stone.</i> <i> But evidence found on
land nearby suggests that
during the Stone Age,</i> <i> when sea levels were much
lower, people did live here</i> <i> and in many other
places just like it.</i> <i> And during this period,
our human ancestors make
some of the most important</i> <i> breakthroughs of all time.</i> <i> They learn how to farm,
keep domesticated animals,
use sophisticated tools,</i> <i> build wooden houses
and begin to trade.</i> <i> Then, the last Ice
Age comes to an end.</i> <i> Over the course of
15,000 years, sea
levels rise by 400 feet.</i> <i> And the territory of these
early people vanishes.</i> <i> Their tools, homes and
weapons are washed away.</i> <i> That elemental human story
may help explain the timeless
appeal of the Atlantis legend.</i> PATRICK: There are many,
many stories out there in
the world that recall times when land that was once
inhabited was submerged. Did that information
inform Plato's fiction
about Atlantis? JON: I think there's no doubt,
that almost every culture
in the world has a flood myth, a deluge story, because
we developed, as a species, within this period
of rising sea level. So, that for me, is so
fundamental to understanding
ourselves as a species, that we should be
looking into this. <i> NARRATOR: Plato's story of
Atlantis is about human folly</i> <i> and the destructive
power of nature.</i> <i> Today, the rising level
of the oceans threatens
all coastal communities.</i> <i> Great port cities like
Bangkok, Ho Chi Minh City
and Dhaka are all at risk.</i> <i> And in North America there's
one of particular concern.</i> <i> New Orleans.</i> <i> Sitting on the banks of the
great Mississippi River,
the city's average height</i> <i> is six feet below sea level.</i> <i> This makes it highly
vulnerable to flooding.</i> <i> In 2005, disaster strikes.</i> <i> Hurricane Katrina
causes a massive storm
surge and the levees,</i> <i> designed to protect
the city, are breached.</i> <i> The resulting floods
are catastrophic.</i> <i> Nearly 2,000 people die and
many more are left homeless.</i> <i> And the situation in
New Orleans is getting
worse, because the</i> <i> city itself is sinking.</i> <i> Due in part to the removal of
groundwater, some districts of</i> <i> New Orleans are subsiding
by two inches a year.</i> JIM: Given ongoing
sea level rise, which
is a scientific fact, the time will come when
some of our settlements in
our time are under water. Cities like New Orleans,
they all have suffered
incursions of water. And the time will come when
we will no longer be able
to battle that incursion. <i> NARRATOR: By the turn of the
next century, New Orleans
could be uninhabitable.</i> <i> A mysterious underwater
city, studied by
maritime archaeologists.</i> <i> A modern-day Atlantis.</i> Captioned by Cotter
Captioning Services.