[music playing] DON WILDMAN (VOICEOVER):
For thousands of years, the isolated islands of Japan
have dominated the world stage. But on its way to
the top, Japan had to survive catastrophic
destruction, and did it by going underground. Can you see these bats? Whoa, hundreds of them. DON WILDMAN (VOICEOVER): From
a super bunker that survived the nuclear blast in Hiroshima,
shown for the first time on national TV. DON WILDMAN: If you were
going to be anywhere for an atomic bomb
explosion, this would be where you'd want to be. DON WILDMAN (VOICEOVER):
To mountain fortresses built to house the entire
imperial government and subterranean
mega structures that can save the city from the
strongest earthquakes-- Look at this. I mean, this is a big
civil engineering. DON WILDMAN (VOICEOVER): --and
the most devastating floods. There's a layer of mist. DON WILDMAN (VOICEOVER):
And even the secret hideouts of ancient ninja warriors. Take a look at how
far this goes down. [inhales] DON WILDMAN (VOICEOVER):
It's the real story of Japan's success, and
it's all underground. We're peeling back
the layers of time on "Cities of the Underworld,
The A-Bomb Underground." [music playing] I'm Don Wildman. I'm in Tokyo, Japan, one of
the most populated and busiest cities in the world. 35 million people
call Tokyo home, but creating this glittering
mega city has not been easy. Over the past 500 years,
Japan and its bustling capital have been rocked by regular
and catastrophic disasters-- fires, earthquakes,
monsoons, wars. It's even been devastated
by two atomic bombs. So how has this relatively
small island nation managed to survive the ravages
of nature and warfare to become one of the wealthiest
and most advanced societies in the world? Well, in Japan, the answers
are closer than you think, but they may be hidden
just beneath your feet. [music playing] DON WILDMAN (VOICEOVER): Today,
Japan is an economic powerhouse on the cutting edge of
engineering and technology. But a hundred years ago, it
was a military powerhouse ready to take on the world. They began an era of conquest
across Asia and the Pacific Ocean, then the Japanese
struck Pearl Harbor in 1941, and the US was in it to the end. It was the beginning of a war
that would mark the greatest challenge for Japan's
fabled warriors. The entire nation, including
boys and girls in grade school, was called on to help
with the war effort. They had sworn to
fight to the end, but they had no idea what
was about to hit them. [explosion] This building is called
the Atomic Bomb Dome, and it was nearly crushed in
the massive nuclear explosion. But it remains one of the
few buildings to survive. The bombs epicenter was about
150 yards away from here, and almost everything, and
everyone, within a mile radius of it was instantly incinerated. But there were a few lucky
ones who miraculously survived in Hiroshima's underground
and lived to tell their unbelievable tales. DON WILDMAN (VOICEOVER):
Only a handful of people that survived
the explosion are still alive today, 76-year-old
Yoshi is one of them. I'm honored to meet you. So we are right outside
Hiroshima Castle. DON WILDMAN (VOICEOVER):
In the heart of Hiroshima, just a half mile to the
north of the A-Bomb Dome, is the Hiroshima
Castle compound. The 16th-century wooden castle
was destroyed by the bomb, but the 10-foot thick walls that
protected the moat of Hiroshima castle were an ideal location
for a military headquarters. And thanks to these
500-year-old stones, Yoshi was the very first
person to report the bomb to the outside world. Fellow atomic bomb
survivor Keiko Ogura helped to translate. Today, for the first
time on national TV, Yoshi is taking us
underground to the spot that saved her life. --entrance of the bunker. This is the entrance
to the bunker here? Yes. OK. Try not to open like this,
something like this, you know? Kneel down and enter. [music playing] How much concrete's up here? And then the castle
wall beyond that? No wonder it could
resist a blast. There is the
officer's entrance. Ah, this door here. Yes. First and foremost,
this is a bomb shelter. This happens to
be where they made a lot of military decisions and
coordinated defenses and air raid alerts from this room. But look at how
substantial this is. If you were going to be anywhere
for an atomic bomb explosion, this would be where
you'd want to be. There's about 6 feet of concrete
over there, plus castle walls, and over your head,
another 6 feet of concrete. DON WILDMAN (VOICEOVER): The
bunker consisted of four rooms. The largest room was
strictly for army commanders. The other three rooms were
for administrative workers and telephone operators,
like 14-year-old Yoshi. The southern wall was
protected not only by the 10-foot
thick castle wall, but by an additional 3
feet of reinforced concrete that surrounded the
entire structure. The northern wall, however,
was open to the main courtyard of the castle and had thick
steel blast-proof doors that could be closed when air
raid warnings were sounded. Now, where did
you work down here? [speaking japanese] In this room? This was your office? DON WILDMAN (VOICEOVER):
Like many young students, Yoshi and her classmates
were mobilized to work for the military. She was supposed to be relieved
of her duty the night before, but American bombing raids
in the surrounding cities kept Yoshi and her
classmates busy. You were supposed to have left
the bunker by that time, right? DON WILDMAN: A twist of fate. DON WILDMAN (VOICEOVER):
While Yoshi was waiting to be relieved, she got a
message that an enemy plane had flown into radar range. At 8:13 AM, an
American B-29 bomber called the Enola Gay
entered Hiroshima airspace. Seconds later, Colonel
Paul Tibbets and his crew released the nuclear
bomb called Little Boy. You've gotten the warning
that the Enola Gay has come over the city. But strangely, it's a low-level
warning, not an urgent one, and so you take that notice
and run back over here. [explosion] DON WILDMAN (VOICEOVER):
The nuclear bomb exploded 2,000 feet
above downtown Hiroshima. The 9,700 pound bomb was
carrying 130 pounds of uranium 235. A conventional explosion
shot two pieces of uranium at each other, setting off
a nuclear chain reaction. The heat of the blast
reached 1.8 million degrees, burning almost 200 times
hotter than the sun. The bomb exploded with
the destructive power of 15,000 tons of TNT. That's 2,000 times more
powerful than the Grand Slam, the world's next largest bomb. Because it exploded
2,000 feet in the air as opposed to at ground level,
the radius of the destruction was actually increased. Had the bomb exploded
near the ground, the earth would have
absorbed most of the impact. But at 2,000 feet, the shockwave
reflected off the ground at 1,000 miles per hour,
faster than the speed of sound, and spread out along
the surface of the city. It melted glass bottles
1,000 yards away. Birds flying nearby
burst into flames. Yoshi's bunker was
just a half mile to the north of the hypocenter,
but thick castle walls and reinforced
concrete protected her from the initial shock wave. But the force of the blast
created an area of low pressure near the epicenter, and
less than 10 seconds later, a reverse shock wave
came from the north, blasting through
the open windows. So you were blown back from
over here all the way to here. DON WILDMAN (VOICEOVER): Yoshi
eventually crawled her way out of the bunker. She walked out to the river and
was among the first to witness the terrifying scene. Within a mile of
ground zero, only incredibly-thick concrete
structures survived. Throughout the city,
90% of the buildings were either crushed or
burned beyond repair. This bunker is one of only
a handful of structures that still exists today. After seeing that her
city had been destroyed, Yoshi immediately
returned to the bunker and found a working phone. DON WILDMAN: They
didn't understand. DON WILDMAN (VOICEOVER): No
one could comprehend what 14-year-old Yoshi was
saying, but she was, in fact, the first person to report
to the outside world what had happened in Hiroshima. After she got off
the phone, Yoshi went to look for her classmates. So you've gone to
look for the girls who were supposed to replace
you but never showed up. Yes. And what did you find? DON WILDMAN (VOICEOVER):
Most estimates say that 70,000 people
were instantly incinerated at the moment of the
explosion, tens of thousands more died from the raging
firestorm that engulfed the city for 12 hours. By the end of the year, 140,000
people, mostly civilians, had died from one bomb. Because of the radiation, many
said that nothing would grow in the city for 75 years. But the survivors rebuilt, and
today, Hiroshima is, again, a bustling city. The A-Bomb Dome and the bunker
that saved Yoshi's life are two of the only grim
reminders left behind by the hell of a nuclear bomb. DON WILDMAN (VOICEOVER): Before
the nuclear explosions rocked Hiroshima and Nagasaki,
the emperor's game plan was to hunker down until the
Allies invaded the homeland, and to do that, he'd need
a secret super bunker, an underground seat
of power off the map and unknown to the Allies. In late 1944, three
years after the attacks on Pearl Harbor, America had
gained ground in the Pacific over the Japanese. The clock was ticking. Soon, American B-29 bombers
could strike the Imperial Palace in Tokyo. So to protect the
emperor and his army, military planners came here
to the highlands of Nagano with designs to engineer an
indestructible fortress deep inside these mountains. DON WILDMAN (VOICEOVER):
The Americans were hoping to bomb the
Japanese into surrender. But from ancient times,
a strict warrior code called Bushido dictated
how the Japanese fought. Every Japanese
soldier and civilian was sworn to defend the
homeland at all cost. Surrender was not an option. Today, the bunker is hidden
away in a quiet residential neighborhood in the town of
Matsushiro just outside Nagano. You'd never guess it's just the
tip of the iceberg for what's beneath. Thousands of miles away outside
of London, Winston Churchill had his secret bunker, and here
in Japan, the emperor had his. Local guide Haruko
Matsuo was going to lead me to the entrance. What was it about
this area that was attractive to the
military planners? A very defensible position. And we need one of these, huh? OK. Boy, it's a really
low ceiling, huh? [music playing] DON WILDMAN (VOICEOVER):
Today, much of the complex is collapsing, but
60 years ago, it was built to be
the wartime nerve center for the empire of Japan. How big is this
mountain above us? So there's, like, a 1,500 foot
mountain over our heads here? So it was protected pretty
well from the bombing just by virtue of the
size of the mountain. And what was going
to be down here? What did they have-- OK. The whole Japanese
government-- Yeah. --would have been-- Mm-hm. --transferred from
Tokyo to these tunnels. Yeah. DON WILDMAN: If this ever
happened in the States, I mean, they would be moving
the entire government. You'd be moving thousands of
workers from the Pentagon. The Congress, the White
House, all the departments, the whole workings of
the federal government would be brought
inside of a mountain. DON WILDMAN (VOICEOVER):
The Japanese emperor was considered
sacred and his power was absolute, so the bunkers
built to protect his authority had to be the strongest
on the planet. The massive structure
was designed by engineers in a strict grid pattern. First, 10 tunnels were
dug through the mountain north to south. Next, they dug another 20
tunnels running perpendicular. Together, the total
length was nearly 4 miles, creating over 2 million cubic
feet of the safest office space in the world. The first line of
defense was the mountain. Mount Zozan soars 1,500
feet above the tunnels, but this was just one
part of the master plan. Two other hideouts were built
beneath neighboring mountains, one to hold the
Imperial Palace and army headquarters and another to
house the emperor and empress. Haruko, doesn't it amaze
you that human beings can even do this, I mean, by hand? And who was doing this? Who mined these tunnels? At once? So they were
enslaved to do it, literally brought from the
Korean peninsula down here and made to do this. DON WILDMAN (VOICEOVER):
Because just about every able-bodied man in Japan
was fighting in the war, machinery and manpower
were stretched to the breaking point. Since Japan had occupied Korea
in 1910, thousands of Koreans were conscripted to work on
projects like Matsushiro. For them, these
tunnels were hell. The process was tedious. At best, miners would
move 10 to 15 feet a day. In nine months,
the 6,000 laborers had finished nearly 80%
of the tunnel system, and the emperor's grand
plan was nearly complete. But six days after
the atomic bombs were dropped on
Hiroshima and Nagasaki, the Japanese surrendered. The tunnels were never occupied. Oh, yeah, look up here. This is the drill hole where
they would have inserted a blast, a dynamite blast,
and that's how they carved off into the dark. The tragedy of
this tunnel system was the death of hundreds
of people, many of them Koreans, who were
forced to do this job. Look, there's a really
cool hole back here. Yikes. Can you see these bats? Whoa, there are just
hundreds of them. This is a big collapse. You can see everything
just fell in here and closed off this
tunnel to everything except an immense
bat population. As far as they were
concerned, there would be no more
Japan if they lost. So as a last resort, they
created a mountain stronghold. From inside here, they might
be able to make a last stand. This is the Sumida
River, lifeline to millions who live along its banks and
one of Tokyo's major waterways. But the same river that feeds
the rice paddies upstream can also create havoc down here. In the last century
alone, monsoon flooding has taken the lives
of hundreds of people, destroyed nearly 300,000
homes, and cost Japan billions of dollars. These destructive floods
used to be inevitable, but now, Japan has
countered mother nature with the most daring
and innovative flood control in the world. It's called G-Cans, and it's
a civil engineering marvel. DON WILDMAN (VOICEOVER):
Much like in New Orleans, large parts of Tokyo
lie well below sea level and along major rivers, leaving
them vulnerable to monster storms like Hurricane Katrina. Both cities have complex
systems of levees, floodgates, and pumping stations to
keep the sea and rivers from flooding the cities. But while New Orleans is home
to just over 1 million people, Tokyo is home to 35 million. If a storm like Katrina
were to hit Tokyo, the consequences
would be unimaginable. And while Hurricane Katrina
rang up a bill of $125 billion, a catastrophic storm in
Tokyo could cost the country trillions. It's only a matter of time
before a storm like Katrina will strike, so faced
with a huge challenge, civil engineers began
to look for a way to stop the destruction. And they found it underground. Just outside the city of
Tokyo, I met Ume Matsua. He's the chief manager of
the massive G-Cans Project. He and his translator,
Justin, agreed to take me into some
highly-restricted areas. So this is the river that
this system is handling, huh? Yes, this is the Kuramatsu-- Kuramatsu. Kuramatsu River, yes. OK, it doesn't look like
a deadly waterway here. JUSTIN: As it is,
it's very gentle. DON WILDMAN: But things
change around here fast. DON WILDMAN (VOICEOVER):
Japan has almost double the amount of rainfall
than the rest of the world, more than 150 inches every year. Some rivers can swell to 100
times their normal capacity, and that's when these
subterranean tanks kick into action. JUSTIN: This is the
number three holding tank. All the water
that's coming off that river, and another one-- Will go into
this vertical tank. --is going into a-- OK, so what is behind
here is a giant tank, and all this water has to
then be sent down below. It's giant. OK, let's go in. [music playing] - Wow.
- Wow. Look at this. Incredible. About a hundred times
more than I expected. So this is where the
water is just pouring in. JUSTIN: That's correct, yes. A giant waterfall
just coming in there. DON WILDMAN (VOICEOVER): 525
feet beneath the rice paddies outside, this is just one
of five massive tanks that help to save Tokyo
from monsoon flooding. The flooding that occurred
in New Orleans after Katrina was caused by a powerful storm
surge that breached the levees. But flooding in Tokyo
would come from upstream where countless small rivers
would become monsters. These tanks are all that
stands between the big city and the deadly torrents. You can see where the color
of the concrete's changed-- Right here. --from the yellow there. It comes up this high. That's roughly around 670,000
tons of water, on average. Yes, that's a lot of water,
and there's five more of these. DON WILDMAN (VOICEOVER):
One of these five tanks can hold 670,000 tons of water. In the case of a
major flood, they fill with rushing water at the
rate of 100 tons per second. When they reach their
capacity, the pump kicks in, moving
the excess water through subterranean pipes and
into another super chamber. Just a mile up the
road from tank number 3 is the entrance to G-Can's
massive central tank. Where is the tank itself? Below this field. This whole soccer field? [speaking japanese] The whole
field here is one big tank underneath us. DON WILDMAN (VOICEOVER): It's
the largest underground tank in the world and sits just
beneath this soccer field. [music playing] Whoa. Oh, it's awesome. This is it? This is the tank. JUSTIN: [speaking japanese] Yes. Incredible. JUSTIN: It's awesome, isn't it? I don't even know what to say. It's bigger than
anything I've ever seen. Look how there's
actually a mist. There's a layer of mist about
halfway filling this thing. It has the feeling of
being natural, you know, even though it's artificial. So these pillars are
holding up the soccer field above our heads. DON WILDMAN (VOICEOVER):
There are 59 pillars in the entire complex, each made
of 500 tons of pure concrete. The massive tank is nearly
two football fields in size and holds nearly nine
million cubic feet of water. It's just awesome. What is this sign here? It's the minimum water
level required before they can activate the pumps. So between these signs
is when the machinery starts working and pumping
this water out of here. And where are the
engines from here? JUSTIN: [speaking japanese] The other end? Right at the back. Take a walk? Should we go? [speaking japanese] DON WILDMAN (VOICEOVER):
Once the floodwaters reach this mark, the pumps kick in. The pumps have an
incredible amount of work to do with millions of
cubic feet of water rushing through the chamber, so they
need an unparalleled amount of power. Using 14,000-horsepower
turbines run by jet engines, each engine moves 50
tons of water per second. Look at that
gigantic machinery. DON WILDMAN (VOICEOVER): The
four combined move 17,280,000 gallons each day. Look at the size
of this machine. This gives you a real idea
of the scope of this project. They need to use a full-sized
jet engine, four of them, to move the turbines that move
50 tons of water per second through these channels
out to the river. And that's how Tokyo
is saved from floods, this engine does the work. So you can see from down
here how high this bank is. There's another bank over
there equally as high. And right down
here you can see-- oh, yeah, there it is-- the outlet flow
chambers right here. Out of these channels
flow the waters that used to regularly flood
the plains and threaten Tokyo but now are safely channeled
out here into this river and then out to sea. DON WILDMAN (VOICEOVER):
In ancient Japan, people climbed to the
highlands to avoid floods. But in today's Japan, they
found a new way to survive-- the underground. The destruction Japan
suffered during World War II was devastating, but this
country is still fighting another more powerful enemy-- earthquakes. Japan is the most earthquake
prone country in the world. Tokyo itself sits on four
active tectonic plates, and a major earthquake is
expected every 75 years. In fact, another big
one is long overdue. So to combat their
most ancient foe, Japan has designed and built
an ultra-modern superstructure in the place where
quakes strike-- deep beneath the earth. DON WILDMAN (VOICEOVER):
The 35 million people who live in the greater
Tokyo area feel earthquakes every week, most of them are
small and hardly wake locals out of their sleep, but
five powerful quakes over the last three
centuries nearly wiped Tokyo off
the map, the worst came on September 1, 1923. The Great Kanto earthquake
struck in the heart of Tokyo. Like the San Francisco
quake of 1906, it's estimated that
it registered an 8.3 on the Richter scale, but
the destruction in Tokyo was far worse, killing almost
50 times as many people. The real trouble started after
the shaking was over as utility lines, like gas and water,
burst, causing massive fires and flooding. It's been over 80 years since
the Great Kanto earthquake, and another big one will
strike, only this time, Tokyo will be ready. It seems crazy that they
would build one of the largest cities in the world in such
a seismically active area. I'm going to meet
this engineer who's going to show me how the city
is addressing the problem. I think this is it. Kenji. Konnichiwa. Wow, this is a
massive project right in the middle of the city. The digging is being
done underneath? DON WILDMAN
(VOICEOVER): Kenji Aguni is a civil engineer who
specializes in earthquake research. He led me into this
highly-restricted construction site in the Toranomon
neighborhood of Tokyo. This is the way down? Yes. All right. Please, after you. DON WILDMAN
(VOICEOVER): In 1963, to protect Tokyo against
the next big one, the city began its most outrageous
and most expensive civil engineering project-- replacing nearly 100,000
miles of major utilities like gas, electric, and
water 180 feet below ground. It's called geosites, and
it all takes place directly beneath central Tokyo. So how deep do we go here? So about 100 feet down. Here we go. [music playing] Wow, look how far
down we're going. Gosh, it's just awesome how
big everything is, you know? Oh, man, look at this. This space is awesome. I mean, this is big
civil engineering. Right. How long did it take
them to build this? Two, three years
to dig this hole. DON WILDMAN (VOICEOVER): But
this 450,000-cubic-foot hole was just the beginning. Once completed, there will
be over 100 miles of utility tunnels throughout Tokyo. DON WILDMAN: So how come they
didn't just use the old pipes? I mean, why did they
have to reinvent this? DON WILDMAN
(VOICEOVER): Earthquakes start deep beneath the earth
where tectonic plates are locked together and begin
to accumulate stress. As the tectonic
plates shift, they release that tremendous
force and begin to shake the earth above them. Because these tunnels are dug
180-feet deep in compact soil, the wavelength of the quake
is over 100 yards wide. So when the shockwave
hits the tunnels, they sway as one whole unit,
but the building foundations and utility lines up
above aren't so lucky. Since the soil on
the surface is soft, the wavelength is
shorter, and the ground shakes more violently,
rupturing vital utility lines. Utilities inside geosites
suffer less damage than their counterparts above. These utility tunnels also
make it easier for city workers to maintain them. OK. So it's got its own
little compartments, and then above our heads,
the train is running. Right. It's an active underground. DON WILDMAN (VOICEOVER): Just
20 feet above is Tokyo's metro. It's the second largest
subway system in the world. Like geosites, Tokyo's subway
was built to withstand even the strongest earthquakes. In fact, if a major
quake strikes, Tokyo's crowded underground
is the safest place to be. And because these
tunnels run so deep, these massive concrete segments
were specially designed to keep out groundwater. So three feet, two hours. Wow. So every time it goes 30 feet,
they've spent a million bucks. Right. DON WILDMAN (VOICEOVER):
Even the project management has no idea how much
geosites will cost, but they do know it's
Japan's most expensive civil engineering project ever. So this is-- really, we're
in the middle of the action. I mean, this is still being
constructed down here. We're standing in the
most basic of tunnels, and they're still
doing a lot of work. They have to build up
platforms for the piping and the structures that will
hold up the utilities that are going to run
through here eventually. DON WILDMAN (VOICEOVER): Most
Tokyo residents will never see the vast tunnel system
that runs beneath the streets, but when the big one strikes,
it will not only save lives, it will also save the city. Ancient Japan was a
constant battleground, with feudal warlords
or shoguns fighting over every inch of land. To protect their properties,
they employed an elite group of warriors called samurais. But in this particular
region just outside Kyoto, Japan's ancient capital
for over a thousand years, a new and lethal kind
of warrior was spawned. Known for stealth,
cunning, and skill, these warriors followed
a strict code of honor. They answered to no one. They were called shinobi-- or ninjas. [speaking japanese] DON WILDMAN (VOICEOVER):
Watanabe [speaking japanese] lives near Koga and is a
descendant of a legendary ninja clan. Now, your family were ninjas. Yeah. OK, so they had a cover. What did it mean to be a ninja? Yeah. DON WILDMAN (VOICEOVER):
Ninjas were known to operate in the 14th century,
but because they were highly secretive, they may have been
around for centuries before. They were well-trained
operatives specially skilled in espionage. Ninjas also employed a
variety of weapons and tricks like smoke bombs and
firecrackers that helped them escape by creating a diversion. Even landmines were constructed
that used a mechanical fuse or an oil-soaked string. Secrets of making desirable
mixes of gunpowder were strictly guarded
in many ninja clans. They were magicians, knowing
how to seem invisible. They were also experts
in the art and science of assassination. Their samurai counterparts
were strictly the subjects of feudal lords, but the
ninja were independent, living in small family groups
and operating in total secrecy. And they were ninjas? Yes. Living right in here. Yes. Yes. All right, thank you. Please. Beautiful. [music playing] Upstairs? I'll see what I can do. DON WILDMAN (VOICEOVER):
The Koga house has been around since
the 17th century. Filled with false walls, trap
doors, and hidden passageways, the house was protecting
more than the ninja family, it was protecting
their secrets-- It's very dark and cramped. DON WILDMAN (VOICEOVER):
--whether it be classified information or even the
fact that they were ninjas. And if a local warlord
raided the house, they could not only escape,
they could disappear. If they got this
far, they're fighting in very cramped quarters. Early alarm system. Every floor has
another lookout place. Every wall might be
another trap door. This house, in the
event of battle, would have been
their best weapon. Oh, here we go. Oh, yeah, third floor. If the battle came
this far, this would have been their
last stronghold, the final stand right up here. He said that there was
another escape hatch. Maybe if we go back down. Listen to how creeky it is. If you were up here and the
attackers were down below, you'd have to remain
perfectly quiet. You'd have to be
stealth, a ninja. I, on the other hand, am
not, and you'd hear me. But that gives you an idea of
how skilled these people would be, agile. I don't know where
you go to get-- there we go. Yes. [laugh] There we go,
the secret passageway. DON WILDMAN
(VOICEOVER): The ninjas who lived here followed
a strict code of honor. And according to
ancient ninja text, justice was their most
important teaching. But because they lived
such secretive lives, ninjas had reputations
as criminals or thieves. And because they protected
highly-valuable secrets, they were often the target
of raids by local warlords. And if none of their trap
doors, secret hatches, or escape routes worked, they
had one last resort-- underground. Well? This is a well? Yes. Oh, you can escape
down there in there? Right. Oh, you can see
the other tunnel. It's submerged, but there's
a large escape tunnel under there. Yeah, I gotta take
a look down there. I mean, we came expecting a
lot of secret passageways, false walls, and so forth,
but this is much better. This is an underground,
submerged tunnel. DON WILDMAN (VOICEOVER):
The first hole was originally built as a well,
but that was just a decoy. The ninja family dug a
tunnel leading from the well 100 feet out to the
fields behind the house. If they were
desperate to escape, they could disappear under
the closet, out the well, and through the
tunnel to safety. Originally, the water
level was lower, but because the rice paddies
have been seasonally flooded, the tunnel is now
completely submerged. So has anybody
ever been down there? No? No. All right, here we go. It's cold. Yeah, it's about
10 feet down here. Oh, it's really, really cold. Oh, yeah, the bottom
is nice and soft. The tunnel is
really well formed. I'm going to go in there and
take a look at how far this goes down. [deep breaths] [music playing] Yeah, it's fully
blocked in down there. It's been collapsed down. But, I mean, I was fully in
there, complete my whole body. So they would have
gotten away this way. You wouldn't have found them. DON WILDMAN (VOICEOVER):
The ninja house in Koga is a relic of a long lost art. When Japan was once again ruled
by a single powerful emperor in the 1800s, the
need for ninjas faded. Ninjas may not have been
the first spies or assassins in the world, but throughout
history, few have ever attained their level of expertise. They were exceptional
fighters, but their method of operation and code of
honor were typical of Japan's unique culture. It's a nation that's overcome
floods, earthquakes, and war, and thanks to its
vast underworld, Japan is still on top. [music playing]
