[dramatic music] NARRATOR: The world's oceans
are littered with evidence of massive earthquakes,
mysterious floods of biblical proportions,
ancient tsunamis-- mega disasters that have
destroyed whole ancient cities and made them sink
beneath the waves. Now, all over the
world, scientists are setting out to
discover the secrets buried on the seafloor in their
search for the lost cities of the deep. [dramatic music] The legend of Atlantis-- an earthly paradise that existed
before the great civilizations of Egypt, Greece, and Rome-- a mega metropolis destroyed
by a natural catastrophe, now submerged beneath the waves. But in their search to
explain the legends, archaeologists are finding that
truth is stranger than fiction. Entire cities really
were lost to the oceans through one or more
ancient catastrophes, and only now are their
secrets being revealed. Are these ancient Japanese
pyramids 8,000 years older than the Great Pyramid of
Giza in Egypt, the remains of the world's first city,
or are they just strange natural formations? Off the coast of
Britain, a discovery that could reshape history-- have divers found evidence
that the biblical flood of Noah was real? In India, one of the oldest
civilizations in history, comes a story straight
out of "Indiana Jones." This spectacular temple has
stood for over a thousand years. But legends, passed
down from generation to generation since
ancient times, tell that it was once one of
seven that had mysteriously disappeared. [THUNDER RUMBLING, LIGHTNING
CRACKLES] Now, under
shark-infested waters, the riddle of what happened
to them may be solved. Off the coast of
modern day Israel, researchers are discovering
evidence of a miracle invention over a thousand years
ahead of its time-- concrete that sets underwater. One of the first places to look
for ancient underwater cities is along the coast,
at the sites of ports. And none are more famous in all
antiquity than this megaport on Egypt's North African coast. Founded by the most successful
general of all time, Alexander the Great, the city
still bears his name-- Alexandria. At its height, Alexandria
was a bustling super city, one of the largest
in the known world. It had one of the biggest
ports in antiquity, with 200 cargo ships rumored to
have passed through its harbor walls daily, twice
as many as pass through New York's Harbor today. The harbor was guarded by
a 400-foot high lighthouse the Pharos of Alexandria,
one of the seven wonders of the ancient world. So important was the city that
it was crowned the capital of Egypt for a thousand years,
second only to Rome in size and wealth. In its heyday, Alexandria must
have been the most fantastic place to visit. It was very rich. It was very sumptuous. And it was a real magnet. So anyone who was
anyone came here. NARRATOR: But it was not alone. Alexandria formed part of a
massive built up development along miles of coastline, not
unlike the continuous band along America's
Northeastern coast. But, incredibly, next
to nothing remains of this awesome metropolis. Today, the coast is bare. How did it disappear? The answer lies under
the Mediterranean Sea. Around 12 centuries ago,
a massive earthquake rocked the North African shore. Alexandria, unfortunately, was
built in a high seismic area, which suffers from a
lot of earthquakes. In fact, between the 4th
century AD and AD 1400, there were something like 23
earthquake events historically recorded. [THUNDER RUMBLING, LIGHTNING
CRACKLES] NARRATOR: In 365 AD, a
destructive earthquake, accompanied by a
huge tidal wave, killed over 50,000
Alexandrian citizens, sinking most of the
city's famous landmarks to the bottom of the ocean. And it is here that
scientists must begin the search for Alexandria. Amazingly, their quest begins
as far away from the sea as it is possible to get. Here, geostationary satellites
of the type used by the US military are equipped
with high-powered scanning photographic technology,
capable of seeing what lies beneath the waves. This is a satellite
view of the west of the delta of the Nile. You have here Alexandria. And here's a bay of Abu Qir. And in color you have
always the sunken land that we have
discovered below water. NARRATOR: Using geophysical data
from their satellite surveys, Franck is able to
build up an accurate picture of the ancient
topography of Alexandria. Let us zoom now on
Alexandria's side. On this satellite view of the
modern city of Alexandria, you see in yellow all the
sunken land and port structure which are now under the sea. NARRATOR: The
mapping of Alexandria has revealed new information
on the sunken city. Its infrastructure is
larger and more substantial than researchers had
previously believed. The underwater teams
diving in the area are constantly faced with
the problem of pinpointing their excavation sites due to
poor visibility at the depths they work. FRANCK GODDIO: We have developed
specific tools for positioning, like underwater
differential GPS, which are precision of a centimeter. And it's extremely efficient for
contours of land and et cetera. When you are doing a
specific excavation, we put the grids, like on land,
and it's easier, of course. NARRATOR: Without this
technology, Franck and his team would be unable to mark
out underwater grids that are excavated one at a time. It's a meticulous process that
takes great patience and care. Using a water dredger-- a kind of underwater
vacuum cleaner-- the archaeologists
remove the sediment in search of artifacts
on the seabed. The potential
for site underwater is that they have not
been looted for centuries, like some site on land. And, furthermore, it's
totally empty space. You can go wherever you want. You don't have a road. You don't have new buildings. You are absolutely free
to expand your excavation into a direction you want to go. NARRATOR: At depths of
between 10 and 20 feet, the excavations of 2007
have provided further clues to the port's destruction. Byzantine gold coins, dating
back to the 7th and 8th century AD, are being uncovered. No artifacts of later
date have been unearthed, leading the mission to believe
that the areas of the port that survived the destruction
in the 4th century were finally submerged
in the 8th century AD. But it is not only
small objects, like these beautifully preserved
golden rings, that the team is discovering. Egypt's underwater
sites are littered with large sunken treasures,
including sphinxes, statues, and stone blocks complete
with royal signatures and hieroglyphs. On Antirhodos Island, we have
discovered a small sanctuary of Isis, with a beautiful
statue of a priest of Isis, very well-preserved sphinxes. On the Poseidium, we found
a full-walled temple. NARRATOR: The new findings
echo the descriptions of Strabo, the Greek geographer
who visited the city in 25 BC. Unlike ancient sites
on land, the artifacts waiting to be
discovered underwater have, for centuries,
been free from looting, offering archaeologists
a fascinating insight into Alexandria's once
glorious ancient past. The team has discovered
over 10,000 artifacts from their 3,500 dives. But this is only the start. The work is ongoing. So there's still many, many
more treasures down there. But, in a way, I think that's
one of the romantic things about Alexandria. It's almost like Atlantis. It really is a lost city. NARRATOR: But despite
its fame, Alexandria is not the largest
port in antiquity to mysteriously disappear. Off the coast of
Israel, archaeologists are searching for evidence
of a huge harbor wall. Hundreds of blocks-- some
weighing up to 50 tons each-- lie on the seabed, and
are believed to be part of a 2,000-year-old megaport,
the New York Harbor of its day, that lies 25 feet beneath
the Mediterranean. Can our team of
underwater detectives unravel the mystery
of the disappearance of the ancient world's
largest harbor and unlock its engineering secrets that
have been lost for thousands of years, secrets that
could revolutionize our understanding of technology
in the ancient world? The "Ancient Discoveries" team
is in Caesarea, modern day Israel, the site of the
ancient world's largest port, investigating its
disappearance into the sea. This incredible megaport
protected up to 300 ships, and opened up the
world of travel to thousands, kick-starting
trade networks and ancient immigration
in the Roman Empire. This was the first
globalized empire. And to globalize
an empire, you have to have great forms
of communication, from your roads, that
we all know about, to actually the ports itself. You need central ports that
can take the supertankers of the age filled with the
fruits of globalization. NARRATOR: Caesarea was named
after the great Roman emperor, Julius Caesar. It was built by the
Jewish King Herod to be the major port in the
Roman protectorate, Judea, and the largest port in
the eastern Mediterranean. The harbor itself was
unbelievably huge, big. Nobody could see such a
big structure worldwide. It was the largest structures
on Earth at the time. 90,000 square yards,
that's a huge area. NARRATOR: Trade from
as far away as Burma flowed across Asia
and the Middle East to satisfy demand in the major
European cities of Athens and Rome. This trade needed a megaport. Thousands of men were recruited
from all corners of the Empire to begin the 12-year project. He created water regs that
was 180-feet wide, huge. You could have a
highway on top of it. And it extended deeply to
the sea, almost half a mile into the sea. NARRATOR: The eastern
Mediterranean can be rough. A powerful wind blows up
from the continent of Africa every summer, whipping
the sea into a frenzy. The engineers needed to create
a massive, solid breakwater to protect the ships
that lay within the port. To solve this problem, they used
the very latest in cutting-edge Roman technology, a substance
that most people would believe is a creation of
modern engineering-- hydraulic concrete, a
technological advancement that underpins all of
today's mega harbors. Professor Robert Holfelder
has been investigating how King Herod's Roman
engineers created concrete that incredibly
could set underwater. I'm standing today in front
of a large kiln at a cement factory where we are
attempting, or this company is attempting, to reproduce what
nature had done for the Romans thousands of years ago. Perhaps we'll be able to learn
something from the ancients by studying the Roman concrete. NARRATOR: This modern
plant in the UK takes limestone from
the nearby quarry, then filters and mixes it with
alumina, silica, and water. In a massive industrial rotating
kiln that uses extreme pressure and heat, it binds the materials
together to create the mortar. The Romans had the same
product, but not this facility. They didn't need it. Nature provided them with
a volcanic dust, which they called "pulvis puteolanus,"
a sand we know as pozzolana, found in the Bay of Naples. NARRATOR: While other ancient
civilizations understood how to make mortar, the Romans were
the first to create what we understand as concrete today. They added rubble to
the mix, or what is also known as "aggregate." The mix underpins all the
Roman super structures built during its
global dominance, like the Pantheon that
still stands in Rome today. And my task, in the last
couple of years, starting with my work at Caesarea, was
to see how the Romans extended this architectural
revolution into the sea. NARRATOR: The Romans were faced
with a problem at Caesarea. How do you make
concrete set underwater? ROBERT HOLFELDER:
What appears to happen is that after the
concrete sets underwater, the pores of the concrete are
so small that, in that sense, the concrete becomes impervious
to the action of the sea. NARRATOR: King Herod's engineers
understood the waterproof qualities of the concrete, and
set about devising construction methods to build the
gigantic port at Caesarea. Herod made the world's first
artificial port in history ever. And he did that in
a very novel way. He didn't take some kind
of technology from the land and apply it to the sea. Instead he used floating chests. They sound quite simple,
these 45-foot long chests, which were really gigantic,
with wooden sides. And those were constructed on
the shore, towed into position, and they make a whole
series of those, arcing out, to create a breakwater. NARRATOR: Into these chests was
poured the hydraulic concrete. SEAN KINGSLEY: As that
set, these wooden chests would descend onto the seabed
and create a beautiful platform for the superstructure
of the port. NARRATOR: Incredibly,
this process is still used today to
build modern breakwaters for the world's megaports. But there still remains
much mystery surrounding the disappearance of the
ancient Caesarea Harbor into the Mediterranean. When you're at
Caesarea now, you only see a very small harbor,
a modern fishing port, with some Crusader
remains on one side. But the main harbor is
completely submerged. And if you swim out over it,
it looks like a natural reef. It's only when you look closely
at the rocks do you realize actually it's not rock at all. It's concrete under
a marine concretion. NARRATOR: Dr. Ehud Galili
is one of the world's leading underwater
archeologists, and has been researching
Caesarea for the last 25 years. His main focus has been
to search for clues to the mystery of the
port's destruction. The magnificent thing is
to go down to see the anchors and the stone still standing
in situ, very well-preserved, to see the towers, to see
everything that was left by the Romans. After 2,000 years, we can
still touch it, and see, and feel what they have seen
and what they have felt here, when they were here. NARRATOR: Dr. Ehud
Galili and his team are coming to the
end of their quest to uncover the secrets of
this lost superstructure. They have discovered the harbor
remains at depths of around 25 feet, and have been
searching for the physical clues as to why the blocks
are submerged. Over the centuries,
a theory has emerged that, like Alexandria in
Egypt, an earthquake destroyed the harbor. The team has pieced
together the clues, and found new evidence
that is unlikely. There was a theory
that a geological fault caused the subsidence of
the west side of the harbor and caused the destruction. Today, we are
convinced, more or less, that the damage or the
subsidence of the harbor was due to the fact that
the harbor was built on top of sand. And the foundation subsided
and settled inside the sand. NARRATOR: Evidence
from the seabed is suggesting that
the ancient world's first artificial harbor,
built with hydraulic concrete, gradually sank over
a hundred years before it was lost to the sea. The world's first
high tech megaport simply sank because
it was built on sand. But ports are not the
only mega structures that underwater
detectives are exploring. In India, the hunt is on for
the Legend of Seven Temples, one of the world's most
mysterious cities in the shark-infested
waters of the Indian Ocean. The Bay of Bengal, 800,000
square miles of shark-ridden waters-- predators lurk, including
the notorious man-eating bull shark, waiting on
their next meal. It is here that tropical storms,
with rotating winds blowing at speeds of 80 miles an hour,
brings cyclones and storm surges to the coast of India. On its southern
coast, local myths tell of a lost ancient city
submerged beneath the waves-- a metropolis, littered like
the legendary Atlantis, with palaces and temples. The myths of Mahabalipuram
have been told for thousands of years, but were
first set down in writing by William
Chambers, a British traveler in the late 18th century. The writings tell of a
once-flourishing ancient city, known to those who visited
as the "Lands of the Seven Pagodas." William Chambers
was the first person to pick up all these
strands of these stories and point out that actually we
can only see one pagoda today. Was it made up? Was this one pagoda so beautiful
and stunning that it got extended into this figure
seven, which has always had a supernatural or
religious importance? Or, as he suspected, did the
other six pagoda temples slide, at some point,
beneath the waves? NARRATOR: The myths, still
repeated by local fishermen today, speak of six temples
submerged beneath the waves, with this temple found on
the shore, the only one of the seven still visible. [non-english speech] INTERPRETER: There were
once seven temples. Six of them are now
underneath the water. Everyone believes
they are lost temples. NARRATOR: Ancient texts have
revealed to archaeologists that Mahabalipuram was once a
flourishing ancient port that reached its apogee
in the 8th century under the rule of
the Pallava Kingdom. This powerful dynasty ruled
southern India for 600 years, growing rich through the
control of important trade routes linked to the spice
trade of the Far East. In the ancient
literature, Mahabalipuram is described as a very
important port town. Of course, as on
date, we do not know where this port was located. NARRATOR: Today, Mahabalipuram
is a bustling town with a population
of nearly 12,000, and contains intriguing clues
for archaeologists searching for the lost temples about the
town's glorious ancient past as a thriving city. These beautifully preserved,
ancient structures, known as the "Five Rathas," date
back to around the 7th century, and were built at the same
time as the missing temples. The complex is carved out of a
single piece of granite rock, a technique that was used
for over a thousand years by Indian architects
and engineers. One of the most impressive
structures to adorn the town is one of the world's
largest bas-reliefs and also dates back to the
time of the missing temples. This magnificent relief, carved
in the mid-seventh century, measures nearly a hundred
feet long by 45 feet high, and covers an entire hillside. But it is this
structure that may hold the key to the whereabouts
of the lost temples. Known as the "Shore Temple," it
is one of the world's greatest ancient treasures,
and a sacred site that has attracted worshippers
for over a thousand years. Local people believe that this
is one of the surviving temple, remaining temples, helping
them as they have been laying submerged in the sea. NARRATOR: If this is one of
the mythical Seven Pagodas, legends tell that it
was once surrounded by a complex of
beautiful palaces and spectacular temples,
built with all the wealth of ancient India's
trading profits, a complex on par with
the ancient world's most sacred sites, like the Acropolis
and the Temples of Karnak. So are the myths a reality? How could something on
the scale of the Acropolis have left no trace? [THUNDER RUMBLING, LIGHTNING
CRACKLES] There seem to be two
processes going on here. First of all, there's
coastal erosion. We know that the sand is eroding
away about one and 1/2 feet every year. So that means 1,500 years ago,
and the shoreline actually would have been something
like 1,500 feet further out in the sea. NARRATOR: The eroding
shoreline in the area may be responsible for causing
the temples to collapse into the sea. But archaeologists
have another theory for their disappearance-- a huge wave. The tsunami of 1797 is
recorded as having picked up a ship of 200 tons and thrown
it one kilometer up the shore, so vicious was the killer wave. And it seems very likely
these were responsible-- whether in one episode
or multiple episodes, we don't actually know yet-- for the destruction
of the Seven Pagodas. NARRATOR: This is
not the only tsunami thought to hit the region. The 2004 Indian Ocean
earthquake sent huge waves over one hundred feet to
the shores of 11 countries, killing over 200,000 people. It also hit Mahabalipuram,
wrecking its shoreline. For a few minutes after the sea
had receded over 500 yards from the shore, and before it came
back as a violent tsunami, local fishermen stood
face-to-face with the answers to this 1,000-year-old legend-- a set of mysterious structures,
once buried beneath the sea. After 30 minutes, go
down very far away, again, coming water, rolling
water, come up. Because I'm a
fisherman, we can-- I saved my things. But my boat, my nets-- other village people coming
just looking for temple. NARRATOR: Captured here by an
eyewitness for the few minutes that they were exposed, this
extraordinary photograph reveals the structures
as the sea receded. Anandan was on the beachfront
as the tsunami wave approached. After I tried to come, and
water coming, and swimming again, the waves coming, the
waves now, sea is coming. I tried to climb to the
trees to take to my daughter. We had a daughter. And also my wife take my son. A possible temple, yeah. I saw a temple in the water. Under the water. NARRATOR: In this
eyewitness image, the tsunami wave is seen here
moments before it crashes against the Shore Temple. The Shore Temple
survived the tsunami, hitting it at 100
miles per hour. The impact of a giant wave was
taken by a sea defense wall. The question now
facing archaeologists is, are these submarine
structures a solid clue that an ancient city lies
beneath this turbulent sea? Dr. Alok Tripathi
is one of India's leading underwater
archaeologists, and has been searching for the
realities behind the myths. Although the seas are
rough, Dr. Tripathi has enlisted the help
of local fishermen to show the "Ancient
Discoveries" team where he has been excavating. In this area, we have got
a number of submerged rocks, which are quite high. And their tops are visible
during the low tide, and found that there are certain
human activity on these rocks. This is the second outer reach. One is very close
to the Shore Temple. They are low lying. And they are not exposed. Located at 100 yards
north of the Shore Temple, the top of the structures
can be seen at low tide. It's a difficult
site to excavate, as the water is shallow and
surges with each breaking wave. The diving there
was not technically difficult on the basis
that it was deep. But, in fact, because it was so
shallow in five to 10 meters, right at the edge
of the Indian Ocean, with huge swells coming
in, it made it very, very difficult to be
stable in the water and to hold onto things. NARRATOR: Trevor, an experienced
underwater photographer who is trained to dive
depths of over 300 feet, has dived the site in search
of the missing temples. Most of the structures are
badly damaged and scattered in a vast area. What we were looking for
initially were evidence of that it was man-made. NARRATOR: Archaeologists
are faced with the challenge of proving how these
structures in the water relate in shape, size, and date
to the temple complexes found just 70 yards from
them on the shore. TREVOR JENKINS:
The Shore Temple-- which essentially is a
large, megalithic structure; it's surrounded by
a low profile wall-- that was very much what we were
seeing initially on the seabed. We had these blocks
in straight lines that correlated very strongly
with what we were seeing at the Shore Temple. NARRATOR: What is clear from
the underwater results is that there is initial
evidence of the presence of the construction
of stone masonry-- remains of walls and
rectangular stone blocks. TREVOR JENKINS: We were coming
across other suggestions that they were man-made, where
the blocks were very sharply cut and set into other
larger blocks, which was fairly good evidence
of a man-made structure. NARRATOR: Archaeologists
believe that this is evidence of the missing temples,
and the findings are related to what is on land. It is very clear
these are man-made. And the architecture
seems to fit exactly with what we're seeing on land. So was the myth of the Temple
of the Seven Pagodas real? Absolutely. NARRATOR: Underwater
archaeologists are really only just at the beginning
of their investigations in mapping out what lies
beneath the waves in the search for this legendary city. Off the coast of Britain,
divers are investigating a global flood of
biblical proportions, one that could rewrite our
understanding of history. Have they found archaeological
evidence of the biblical flood of Noah? [dramatic music] Myths and legends of
cataclysmic floods exist in all ancient cultures,
such as the famous legend of Noah and his Ark. Every civilization tells
the story of the Great Flood that wiped out all
but a few survivors. Incredibly, several great
floods are generally accepted to have occurred as
the result of the last Ice Age, with most of the glacial
melt having finished 8,000 years ago. The ocean filled vast
basins in matters of weeks, in catastrophes that are
unimaginable in today's world. But did these events
spark the flood myths found in all cultures? It doesn't take a lot
of great imagination to understand the impact that
these melting ice caps would have had on these communities. We have historical text
preserved in Mesopotamia, and in Israel, in India,
and as far apart as Mexico. It's very positive to
say that, yes, this was their global flood. NARRATOR: Divers off
the coast of Britain have discovered intriguing
evidence of a town submerged beneath the sea that
may hold the secrets of the mythical flood. Right off the south
coast of Britain is a narrow 40-feet deep
strait between the mainland and the Isle of Wight. The Isle of Wight,
at the moment, is possibly one of the most
enticing, fascinating sights in England. NARRATOR: The divers drop into
water, the temperature of which can drop to 46 degrees. The work here is dangerous. The current in the straits
can reach 3.5 miles per hour. A good human swimmer would have
to swim with all their strength just to stay still. At the seabed, they
reach the site. NARRATOR: Dr. Gary Momber is
leading the investigation. I discovered this
underwater settlement after looking for it about
two and 1/2 years ago, and discovering part of
it, a hearth, a fireplace, underwater. SEAN KINGSLEY: The strata, the
levels, are very, very narrow. And whereas on land you could
use a pick to excavate a Roman town, for example, if you used
similar methods underwater, you'd go through an entire
thousand year level. NARRATOR: The team has marked
out a grid on the seafloor. They carefully analyze
each square's contents, looking for evidence
of human activity. NARRATOR: They remove the
sediment from the seabed in search of artifacts. Over thousands of millennia,
the underwater environment has preserved the clues. Back at the surface,
samples are sieved. But what evidence
will the mud reveal? GARY MOMBER: What I've got
here is a little flint tool. It's been deliberately
made from a block of flint. They've shaped it, and
chopped this bit out. And then they can use it
as a chopping implement. It's very fine, very
distinctive marks on the side, and it also looks like
it's been sharpened. It was found next to
this piece of wood. And this piece wood also
has cut marks in it. And I suggest it was probably
used for the food-making. And on it, it's got a cut mark
straight across the top here. It's been sliced off. Now that was buried deep in the
sediment over 8,000 years ago. And it's just been
recovered, and you can still see the cut marks on it. NARRATOR: Other samples have
produced further evidence of human settlement at the site
dating back eight millennia. But what suggestions are
there that the residents here were evacuated during a
cataclysmic flood 8,000 years ago? TREVOR JENKINS: There's a human
activity layer under there. [inaudible] Yes, all these mollusks
eat their way through it. [inaudible] measure at work. We have the old landscape. We have it covered in
vegetation and trees. We have the underlying geology. And above that, we've
got marine sediment, which show exactly when the
sea came in, and how it did it. And we've got the
dates for that. About 7,950 years ago, I'd say. SEAN KINGSLEY: This site dates
to around the Middle Stone Age, the Mesolithic. They were hunter-gatherers who
moved across the landscape, following the rhythms
of the seasons. NARRATOR: The evidence
found at the site reveals a time before the
English Channel existed, and when Europe and
Britain were joined. But after the melting of the
ice caps, which covered most of northern Europe, sea
levels started to rise, and the settlement was
buried beneath the sea. The Isle of Wight site is strong
evidence of human settlements being destroyed
by ancient floods. But these legends relate
stories of whole cities being destroyed. What evidence is there
of ancient megacities being wiped out by floods
or rising sea levels? Off the coast of Japan, a
furious debate is raging. 80 feet below the surface,
at a place called Yonaguni, lies a mass of
provocative evidence. Could these steps be elements of
a construction that formed part of a huge city temple
complex beneath the sea, a mega metropolis that
dates back 10,000 years? This would make it the
first city man ever built. And if the residents were
capable of this miracle, what other lost secrets might
lie beneath the waves? In 1985, divers discovered
these mysterious formations on the seafloor. The enigma of their origin
remains a controversy among scientists
and archaeologists. Yonaguni is a freak of nature. Or is it a freak of man? It is the monster of the deep. It is the Frankenstein
of marine archaeology. It's this monster
that, up till now, nobody's been able to crack. You would need a Sherlock
Holmes and an Agatha Christie to put on diving gear
and get down there, it's that complicated. NARRATOR: For some scientists
investigating the area, these geometric lines suggest
that the structures are man-made. [non-english speech] INTERPRETER: It is a complicated
stepped pyramid structure, built to provide protection
from enemies it seems. NARRATOR: But, more
incredibly, scientists believe these submarine
structures may date back thousands of years, to even
before the Great Pyramids of Giza in Egypt that were
completed in around 2,500 BC. The question archaeologists
must now answer, is this evidence of the
oldest megastructures in the world ever? Underwater archaeologists are
investigating off the island of Yonaguni in Japan whether
these huge submarine formations are evidence of the oldest
man-made superstructures predating the great
civilizations of Rome, Greece, and Egypt by thousands of years. Professor Kimura,
a marine geologist, has been studying the
Yonaguni site for 10 years, and believes he has
uncovered new information on the date of the structures. [non-english speech] INTERPRETER: At one time, it
was thought that they might be as old as 10,000 years old. But as we have
accumulated more evidence, I have come to think
that it was constructed over a period of time between
3,000 to 5,000 years ago. NARRATOR: But other researchers
have doubts about its age. Well, what is this site? I mean, that is the
$6 million question. This just completely runs
contrary to anything that's ever been found beneath the sea. We have now found settlements
in Nagasaki prefecture beneath the sea, and we
know what they look like. And these things are
dominated by pottery, and flints, and finds. Problem is, at this particular
site, Professor Kimura, there is no pottery. There's no material culture. NARRATOR: What has amazed
scientists studying the area, but also led to doubts about its
existence as a man-made site, is the pure scale and size
of the structures lying beneath the waves. The biggest structure is 600
feet wide and 90 feet high. SEAN KINGSLEY: When you go down
airily under great visibility on Yonaguni, you have this
massive site, which initially looks like a
pyramid in the deep. It's something like
over 900 feet wide. And it's intercut
along its edges with these horizontal planes,
completely smooth, and then walls going up at
complete 90 degree angles. NARRATOR: Labeled as "No. 1 Monument," or "Yonaguni
Underwater Pyramid," it looks like a stepped pyramid,
which investigators believe closely resembles a giant
gusuku from Okinawa, which still stands today. The gusuku is thought to
be a mixed structure-- part castle and part temple. [non-english speech] INTERPRETER: In the
case of Okinawa castles, this could be a sacred
site, like a tomb. This is reminiscent
of a pyramid. It's basically
what we have here. NARRATOR: These perfect
rectangular corners make it difficult to
believe for some researchers that this is a
natural occurrence. When you look at
these surfaces, which are very smooth, they kind
of look like negatives. And I wonder whether,
in the Medieval Period, this site was actually on land,
and what we're looking at here is a medieval quarry. And the stones were taken from
here to the castles on Okinawa. And that is what has given this
particular site its character. And I think that's
something that geologists and archaeologists
need to explore. NARRATOR: If Professor
Kimura's theory is right, the site at Yonaguni is evidence
of an advanced civilization predating Egypt, the first
civilization recognized by most historians as undertaking
massive building projects that have lasted. INTERPRETER: This is a
portion of the Yonaguni site, a 300 to 1 scale model
taken from our surveys. You enter part of a loop
that circles the entire site. Here, the path climbs and is
met by two large sculptures. Past them is the tomb area. We think this is the
most sacred area. NARRATOR: The Loop Road,
described by Professor Kimura, that surrounds the
complex, has intrigued underwater archaeologists. Its widest part
measures 15 yards. And through their
investigations, scientists believe they
have uncovered evidence of an arched gate
at its entrance. With the proposed Loop Road
connecting all the structures at the site, the
underwater region has city-like attributes. This kind of
structural engineering, if proved man-made, demonstrates
a civilization using techniques and technology that was
advanced for its time, but was then lost. Incredibly, only a hundred
miles to the north of Yonaguni, Professor Kimura is
searching for more evidence of massive underwater
constructions. [non-english speech] INTERPRETER: At
Chatan, there are what we believe to be ruins. They have been
visible for 10 years. And we have been trying
to certify what they are. [dramatic music] The Chatan site is situated
off the island of Okinawa in Japan. The "Ancient Discoveries"
team is launching a dive in search of the structures,
using a remote-controlled robot sub to guide the camera
right up to the site. Teams of trained divers
and underwater cameramen prepare to use the latest in
cutting edge diving technology. The remote-controlled robot
submarine, first developed by the US Navy, now allows
underwater archaeologists to record high definition
images at depths of over a mile beneath the waves. Professor Kimura is
leading the search. Attached to an umbilical cord,
the remote-controlled camera feeds images back to the boat. The visibility is remarkably
clear at this site, allowing the divers
to fully investigate the submerged ruins. [dramatic music] Approaching the site, they
find the structures that are believed to be man-made. Underneath the barnacles
and coral, the divers investigate the
wall-like formations. Professor Kimura
believes the structures they are investigating
at the site are similar in their
construction pattern to those found on land
at Shuri and Nakagusuku. MASAAKI KIMURA:
[non-english speech] INTERPRETER: What
we are seeing here is something like
a castle or a fort. MASAAKI KIMURA:
[non-english speech] INTERPRETER: In China,
there are structures like stepped pyramids. And this resembles them. [non-english speech] INTERPRETER: There is
also a marked resemblance to the foundations of castles
at Shuri and Nakagusuku. NARRATOR: Could castles
like this have once existed thousands of years ago
on the islands of Japan, only to be lost to the
depths of the ocean? Were they the centerpiece
of a lost city? [non-english speech] ROBERT HOLFELDER:
The ruins at Chatan were submerged about
2,000 years ago, at the same time as Pompeii was
buried by the eruption of Mount Vesuvius in the Mediterranean. It was the same
tectonic plate movement. NARRATOR: It's incredible
to think that the submarine structures that Chatan may be
linked to a global catastrophe that wreaked havoc
across the globe. [non-english speech] INTERPRETER: I hope that
with this investigation we are able to assess
the effects of tectonics and global warming on the
loss of civilizations. NARRATOR: In the
last two decades, archaeologists and scientists
have made extraordinary leaps forward in our
exploration of the seas. They have unearthed stunning
underwater structures-- pyramids, statues,
streets, and settlements-- that have transformed our
understanding of history. Yet this is just the beginning. We think we know
everything about the sea. But, actually, we've only just
started to scratch the surface. In fact, we know more about
the moon and the face of Mars than we do on the
world's oceans. NARRATOR: In what remains
of the 21st century, our greatest ancient discoveries
will not come on land, but at the bottom of the sea. And with a continuous
rise of sea levels through global warming, will
our modern day megacities one day also become
submerged beneath the waves?
