Nazi Megastructures

It's one of the deadliest islands

in the Japanese empire

a labyrinth of lethal gun emplacements

and concealed killer defenses.

It turned the American troops into nothing more

than a shooting gallery.

On this tiny island,

the Japanese revolutionize traditional tactics...

And use our short swords to slash him

to the very marrow of his bones.

...and lure the Americans into a death trap.

This island-wide megastructure serves one purpose

to bleed the Americans white.

This became known as Death Valley.

This is the story of Japan's Death Island.

The biggest construction projects of World War II,

ordered by Hitler and his Japanese allies...

now these ruins survive as dark reminders

of their fanatical military ambition...

...and America's fight to overcome it.

These are the secrets of the Nazi megastructures.

Peleliu, November 1944.

As a vast American force begins its invasion of the island,

23-year-old Sergeant Keiji Nagai

retreats into the hills.

Nearly at the tunnels!

We'll be safe there!

But it's all part of a plan

to draw the Americans in.

The Japanese have a secret weapon

the island itself.

Remnants of the savage conflict for control of Peleliu

still cover the island today.

Former U.S. Marine and historian Mark Waycaster

is searching for evidence of how the Japanese

transform Peleliu into a death trap.

Look here.

We've got a series of caves here.

It looks like it's part of maybe some massive cave network.

There appears to be another cave a little bit further up here.

I can see a lot of equipment in front of it.

This is definitely one I got to get into.

Looks like I made the right call.

This cave itself, it's not, it's not natural.

It's, it's been dug out.

This isn't a single cave here.

The Japanese have honeycombed this entire area.

This allowed them to remain hidden

as the American troops advanced up into the valley.

It turned the Americans troops

into nothing more than a shooting gallery.

They were like sitting ducks.

And that, in turn, turned Peleliu into a battle

unprecedented in the Pacific War,

one of intense bloodshed,

one that almost broke the Americans.

The story of Japan's Death Island begins in May 1942

with the Japanese occupation of the Philippines...

...a country rich in oil, rubber, and metals

all vital to Japan's war machine.

But by March 1944,

these crucial resources come under threat.

The Americans have swept through the Pacific,

and the Philippines look to be their next key objective.

But lying between the Philippines

and the advancing U.S. forces is the Palau island chain

at its southern tip, the tiny island of Peleliu.

The Japanese know it's in the perfect position

to be a thorn in the side of the American advance,

and they intend to exploit this to the maximum.

Peleliu, a mere speck on the map,

is now of critical strategic importance to both sides.

A battle for control of the island is inevitable,

and the Japanese are determined to make the Americans pay,

in blood.

Japanese Prime Minister Hideki Tojo

tells generals and admirals

that they must make the battle as costly as possible

for the Americans.

In April 1944,

the Japanese rush troops and supplies to the island.

Put that box over there.

Among them is 23-year-old

Sergeant Keiji Nagai.

This island is so peaceful and green.

It's hard to believe we're preparing for battle.

Commanding the defense of Peleliu

is Colonel Kunio Nakagawa.

At 46, he's a seasoned veteran

and a highly regarded military leader.

Show me that.

6,500 disembarked. That's everyone.

Nakagawa's orders are clear.

When the Americans launch an invasion,

he is to make them pay heavily.

But the Americans have already gained

an advantage over Nakagawa.

On March 30, 1944, the Americans had launched

a mass shock bombing raid on Peleliu,

their target its vital airfield.

Airpower historian Mike Pavelec

is searching for evidence of the Americans' air assault.

Oh, yeah, this is what I've been looking for.

Oh, this is fantastic!

So, it's a Zero fighter, a Japanese fighter plane

in the middle of the jungle.

This is amazing!

The Japanese Zero is a single-seat

air superiority fighter,

one of the finest fighters of the Second World War.

This example was part of the air defense force of the island

the Japanese had here.

So, the red here on the wings,

and there would have been one on the fuselage as well,

was the national insignia of the Japanese empire.

So, the red meatball that the Americans called it

makes for a nice target designation,

but it would have been painted probably mostly white

with the big red circles

on the wings and on the fuselage.

This airplane that's still sitting on its landing gear

but with a broken back,

to me looks like it was destroyed on the airfield

as it was parked, with high-level bombing raids

that the Americans did

to neutralize Japanese airpower here.

The American air raid in March 1944

wiped out around 160 Japanese planes,

many of them still on the ground.

It's an early move to soften up Peleliu

ahead of an amphibious assault

and a significant setback for Nakagawa's planned defense.

The Japanese have no airpower

to help protect them from the imminent American invasion.

And that invasion grows ever closer.

By May 1944, the Americans are just over 1,000 miles away.

The northern force is closing in on Saipan

in the Mariana Islands

while the southern force captures the Admiralty Islands

off the coast of New Guinea.

Both are moving inexorably closer to Peleliu.

Colonel Nakagawa has a huge task ahead of him.

He decides to follow the traditional strategy

of focusing almost all his defensive efforts on the beaches.

They will target the beaches

in the southwest.

It is by far the best place to land.

Positions should be prepared in an interlocking fashion

and defended with fierce fire to destroy the enemy

at the water's edge.

Defensives should be completed in a month.

Understood?

With the American juggernaut rapidly closing in,

Nakagawa needs to act fast.

May, 1944.

On the tiny Pacific island of Peleliu,

over 10,000 Japanese troops

prepare to inflict maximum damage

to the approaching American forces.

Six miles long and two miles at its widest,

Peleliu is an island of extremes.

Its coast is largely surrounded by reefs,

impassable mangroves, and dense forests,

limiting viable landing beaches for any invading force,

but perfect for Nakagawa

and the placement of his coastal defenses.

Sergeant Keiji Nagai and his men

are put to work at the water's edge.

Keep it up! Japan is depending on you!

Remember, our orders are to defend this island,

even if it means death.

Historian Professor Geoff Wawro

is scouring Peleliu's coastline for the defenses

designed to force the Americans back into the sea.

As Colonel Nakagawa planned

the defense of Peleliu,

he focused on beaches like these.

You've got a lot of mangrove swamps or jagged coral shelves.

This is a sandy beach.

And Nakagawa has prepared a warm welcome.

I mean, this is the classic Japanese bunker,

perfectly positioned,

sited to enfilade that beach with heavy fire.

It merges naturally with this coral cliff

that extends out to the beach,

so that if you were flying a Navy recon mission

looking for targets,

it would be very hard to distinguish this bunker

from this, this coral cliff beside it.

There's an entrance back here.

Well, there would have been

a lot more head room in this bunker

before it was filled in with sand and coral.

And it has a very well-preserved

37-millimeter gun.

This has a perfect field of fire,

and it's just part of a larger system of bunkers.

You are going to have mortar men dug in, light machine gunners.

All taken together, it is the perfect killing ground.

If the Marines hit this beach,