All language subtitles for Secret.Nazi.Bases.S02E03.Hitlers.Secret.Underground.City.1080p.AMZN.WEB-DL.DDP5.1.H.264-BurCyg_track3_[eng]

- [Narrator] The Nazis carved
an underground city,

hidden in the forest of Poland.

- The woods are
concealing something
really profoundly dark.

- Miles of tunnels burrowed
into the mountainside.

- You really can only tunnel

through this material with
drilling and blasting.

[blast exploding]

- [Narrator] So much
remains unknown.

- You look at these
tunnels, it's eerie.

There's still materials,
equipment left.

It looks like people
left in a rush, in a way.

- Most people think
that there could

be hidden German technologies.

- It's built at such
a scale that you

can drive trucks through them.

- [Narrator] Whatever
was stored here,

it would have been immense.

- There is something; it
looks like wooden crate.

- The only way to solve
it is to keep digging,

keep exploring.
[dramatic music]

- [Narrator] Deep in
the heart of Poland,

hidden in the heavily
forested mountains,

a secret project on a huge scale
is undertaken by the Nazis.

- The Owl Mountains are kind
of misty and dark and shrouded.

Very few people live there.

It's a kind of ancestral forest,

more remote than you imagine
for the area in Europe

in which they're
located in Silesia.

The woods are concealing
something really
profoundly dark.

- [Narrator] 1943, the
tides of world War II

are turning dramatically.

Germany is on the retreat,
but the war was far from over.

The Owl Mountains cover an
area of about 77 square miles,

near the historic
lower Silesian Region.

- If you are in this
mountains, you see nothing.

You see some small
holes on surface,

some small pieces of concrete,

some structures that you
cannot identify in any way.

- [Narrator] Here, the
Nazis put into action

a tremendous construction
project known

as the Osowka Complex.

Even with the monumental
resources being poured into it,

they do so in complete secrecy.

- It's certainly clear
that the Nazis were using

that location, sheltered
and remote from the populace

and also from Allied bombing.

- The Nazis did not want
people to know about it.

The entrances to many of
these complexes had shrubbery

and vegetation to
try to hide them.

- [Narrator] Absolute secrecy
is critical for this project.

No one, not even locals, are
allowed near the mountain

for fear of spies
and informants.

- To be able to
keep it a secret,

what do you say to
someone when they ask,

why are you blasting the
side of the mountain?

- The public would not have
known very much about this.

So the public
learned what Hitler,

Goebbels and others
wanted them to know.

- In fact, those people did
not realize what do they build.

There were some gossips
they heard, but of course,

the purpose was secret.

- [Narrator] Locals
are merely told that

The Silesian Industrial
Company was created

to conduct construction work.

- The Nazis were just
obsessed with secrecy.

They had a cult of paranoia
and that was everywhere

one went, the SS or
the Gestapo had eyes

and ears on every
project and every person.

- [Narrator] With the war going
badly on so many fronts,

the construction of this
massive complex is baffling.

- The project has the official
involvement of Albert Speer,

who is one of the right
hand men of Adolf Hitler

and certainly, in
architectural design.

So it has all the hallmark
of a Nazi orchestration

at the very top levels.

And that feeds the questions
about what it was exactly for.

- Many of the projects they
built seem to be unbuildable,

undoable, unrealistic.

Yet they managed to somehow
build these massive facilities.

And what's even more shocking
is they did this in the middle

of a war and while building
dozens, if not hundreds,

of similar structures
all across the continent.

It boggles the mind.

- [Narrator] Though the
project is top secret,

experts believe one
important clue is the makeup

of this specific terrain.

- The Owl Mountains
are igneous rock

and igneous rock is the
old core of the earth,

the oldest rocks that are
on the face of the planet.

- The rock that you
can't easily excavate,

that you can't easily
use hand tools to remove,

that takes a lot of force
to shatter and move through.

- [Robert] They're very dense.

They're not at all like
sedimentary limestones.

These rocks are very
difficult to bore through,

very difficult to
tunnel through.

- You really can only
tunnel through this material

with drilling and blasting.

[blast exploding]

It's an intensive effort.

- I can't think of how
much energy you would need

to blast that rock.

That's a lot of power.

- So there must've
been a very good reason

to build this facility
here than anywhere else.

One of the advantages
of tunneling

through igneous rock
is that it's so hard

and so solid that it pretty
much supports itself.

- And for that reason,

they're also extremely
resilient to any attacks.

[bomb exploding]

- Once you get deep inside that
mountain, you're good to go.

You are protected
from almost anything.

- [Narrator] Creating this
impenetrable site here required

an astounding workforce
to carry it out.

And one that could
also keep silent

about the facility itself.

13,000 forced
laborers and prisoners

from concentration
camps were put to work,

digging out the Osowka Complex.

- What you could achieve
with 13,000 workers,

in sync, being directed
and focused on a task.

You can move pretty quickly.

- Many of the thousands of
forced laborers that died

in these tunnels were
killed by the disregard

of the Nazis for safety
of those workers.

- You're working possibly
under suspended loads that

could give way at any time.

You are working in very
wet and mucky conditions.

You're inhaling, potentially,
a lot of particles,

but you don't have
the safety equipment

that you should be using.

- Third Reich had,
almost till the end,

unlimited human resources,
slave workers, forced laborers,

concentration camps inmates.

So they had so powerful
and huge working power.

- [Narrator] With this massive
force of slave labor

at their disposal, the Nazis
proceeded to remove upwards

of 70 million cubic feet
of rock from the landscape.

- It's a mountain
of itself, right?

You're taking a mountain
out of a mountain.

- So we're talking about
moving 10s of millions

of tons of material out.

To put that in perspective,

an average dump truck holds
probably, maybe 20 tons.

So we're talking about
hundreds of thousands

to millions of dump
truck loads of material.

- [Narrator] With very few
records to shed light

on this project,

experts attempt to pry answers
from the rocks themselves.

- I spent 15 years researching

and exploring places
like Owl Mountains.

And as far as we know,

it should have many
underground complexes connected

to each other as a one system.

- [Narrator] But the layout
and extent of the structures

are confusing and deceiving
to those who explore them.

- In that era, there wouldn't
have been very many tunnels

that had reached that length.

So it would have been
a major undertaking.

- [Narrator] Even more baffling
is the daunting scale

of the construction.

- One of the first
things one notices

is the absolute size
of this project.

It's massive in its scope.

- And obviously
built at such a scale

that you can drive
trucks through them.

- [Brooke] They're for a lot
of traffic to flow through.

- These are not
bunkers and tunnels.

These are underground cities.

- If you want to build
tunnels of this magnitude,

you've got to deforest,
you've got to clear the land,

you've got to provide
a clean water source.

You've got to build roads into
this area that can support

this heavy equipment that
you need to bring in.

You need to build machine shops,

bunkers and barracks
for people living there.

And those alone are a project.

- It would be difficult
for any government today

to build this, not only the
science and the engineering,

but think of the cost.

In today's dollars, we're
talking billions of dollars.

It's hard to imagine
any of these projects

being done today by
virtually any government.

- [Narrator] Even as they
fought a retreating battle

on multiple fronts,

the Nazis concentrated
enormous efforts

to construct this massive
system and do so quickly.

- They advanced
these in two years.

That is an incredible feat.

Moving those at that
rate is madness.

The amount of
manpower and planning

and logistics behind
that, it's crazy.

- And this is 75,
80, 85 years later,

they're still in good
shape today, many of them.

The one thing the Germans
knew how to do was build.

- They built the system
in a protected area.

This was a strategic
place to build something

that was important to them,
that they needed to protect.

- [Narrator] And it's
precisely then purpose that

has many experts coming up
with different theories.

- And at the end of the day,

you can come up with fabulous
notions of what it was,

but you need some sense of
fact, you need documents,

you need evidence to prove
precisely what it was used for.

- We don't have a
lot of knowledge

from the people who built it,

in part because it was
concentration camp labor

and many of them were murdered.

And we don't have a
lot of information from

the local German
populations because they

were all fleeing the
Red Army in 44, 45,

or they were expelled
after the war.

So all of the people who may
have been intimately connected

with the plans for any
of the tunnel systems

or could have been able
to tell us how some

of this stuff fit together,

they disappear after the
war and the documentation,

a lot of it appears to
have been destroyed.

- [Piotr] We cannot say for
sure that all those structures

and all those tunnels
should be connected.

- [Expert] You
know, on one hand,

the Owl Mountains are
full of natural resources

and ores and things
that the Nazis need

to make the war
machine function.

But on the other hand, the
amount of time and energy,

the cost of digging
through just layer

and layer of solid rock,
it really makes no sense.

- [Narrator] Researchers attempt
to piece together clues

as to what the Nazis intended
and following a suspicious,

blocked opening, what
is discovered to be
an elevator shaft,

leads through the mountain,
bank into the forest,

and comes up just near a ruin
known only as the casino.

[dramatic music]

An impenetrable underground
Nazi city appears to

be known only to very
few in the hierarchy.

- The Nazis were
obsessed with secrecy.

They were obsessed with keeping
information to themselves

and not allowing people who
weren't directly involved

in the project from
knowing anything about it.

- [Narrator] Part of this
top secret complex

is hidden behind
trees and foliage.

Known only as the casino,
this building connects

via an elevator shaft
to the larger complex.

The building known as the casino

at the top of the mountain
is rather strange looking,

but by all accounts, it
looks as though it could have

been some kind of command bunker

or perhaps an
observation station.

- [Narrator] This 160 foot
long building juts out

of the ground with
walls 20 inches thick.

- It's a concrete
bunker, it's a tank.

It looks pretty bomb-proof.

Very small window openings,
barrel formed roof,

and it connects directly
down to the tunnels.

- [Narrator] It also
features chimney ducts,

an electric grid and a
nearby train stop with

an elevator shaft leading
to the tunnels below.

- [Expert] You're really
kind of like you're

in a concert hall almost,
except it goes on and on and on.

- [Narrator] Not far
from the casino,

another abandoned ruin gives
way to more secret plans.

Experts only know this
was a power station,

but used to power what?

- You need electrical generators

and a power plant that
can operate independent

of whatever power plant
would be in the area.

- There was a lot of effort
done to get rid of evidence

that would have helped
us understand what
the structure is.

- Could it have been for
developing a new weapon

that was gonna win them the war?

- Some people believe that
all surface structures

at Osowka like casino,

it was kind of a platform
for the first reactor

that Nazis could build
in those mountains.

- [Narrator] Rumors have
long persisted that

the Nazis were on the cusp,

if not already in possession
of atomic weapons capability.

- If I really wanted to
develop some technology

that was well beyond what
my enemies were developing,

I would want some type
of complex like this

that would keep
prying eyes away.

You can control the
flow of people to

and from that complex
relatively easily.

Obviously, it can't
be photographed by
aircraft flying over.

- There is not many stories
about what could be stored

in those tunnels, but most
people think that there could

be hidden some
German technologies.

- Conspiracy theories
that these were designed,

at least in part, to be
underground facilities

for further production of
secret weapons is quite tenable,

which would be consistent
with things where

they took production of rockets

and advanced
scientific experiments

and tried to put it underground,

both for protection and
for further development.

- We know for sure
that the Germans

had moved industrial
facilities underground.

The airplane engines were
being built underground.

The rocket program,
the production,

was moved into
underground facilities.

And so, it stands to reason
that some of these tunnels

could have been
designed as places where

they could continue to
manufacture supplies.

- [Narrator] When the decision
was made to abandon

the complex, they apparently
did so in a hurry.

- When you look at these
tunnels, it's eerie.

There's still materials,
equipment left.

It looks like people
left in a rush in a way.

- When you see these
wagons and hand tools,

chains, almost littering
some of the tunnels,

it does make you feel like
something happened here

to make people suddenly leave.

It's got quite an
eerie feel to it.

- [Robert] It ran out of steam
like the Third Reich itself

towards the end of 1944, 45,

when the Soviet army
starts advancing.

What we do know, without doubt,

is the resources
that went into it.

- [Narrator] While Piotr has
explored many previously

unknown parts of this
underground labyrinth,

there are still areas he
has yet to crack into.

- Now is a guardroom on the
beginning of the complex.

And it's blocked from each side.

So, since World War II,
nobody looked down there,

and there is a little
hole I will try to put

the inspection camera
to see what's inside.

Every time we put
this inspection camera

inside unknown
space, I'm excited.

It's natural because
I still hold that

we'll finally find
some solution,

we will find another
part and we will discover

something important to the
mysteries of the Owl Mountains.

There is something,
some parts of wood,

some rocks, some
parts of concrete.

- [Narrator] Piotr,
like many experts,

believes what we see
is just a small portion

of the construction.

- There are rumors
that won't go away

that there are indeed
more tunnels and
more complexes hidden

in the mountainside
around the Osowka Complex.

- We do not know how that
tunnels should look like

when they would be finished.

We can not even imagine,
because we do not have a plan.

- We know that the Nazis
were planning to redevelop

these tunnels and
develop them further.

We know that they
ordered a huge amount

of concrete for this project.

We know that the precise purpose

of these tunnels
is still not clear.

It wasn't even clear
to senior members

of the Nazi high command.

So all in all,

you've got a mystery
wrapped up within a mystery

and the only way to solve
it is to keep digging,

keep exploring, keep going
down into these tunnels.

- It's really hard to
say what is exactly.

We just see a little
part of the room.

We see that it is blocked.

I will try to put camera,
to dig another hole

to see the space inside
from different perspective.

- Just taking a short cord.

we are inside.

- It is not easy because
we have a free holes

that we can do it.

Definitely inside
are some items we

can't identify at this moment.

What can it be?

- [Narrator] No one has
laid eyes on the room

since 1945 when the Nazis fled.

- It looks like
crate, wooden crate.

If you want to see more,
we have to put more lights.

That will give us view
fr details inside.

- [Narrator] As Piotr
continues his investigation,

another theory emerges.

The large presence of SS
in and around the complex

led many to believe
this could ultimately be

a massive command bunker for
none other than Hitler himself.

[dramatic music]

Digging in the Osowka Complex,

researchers attempt to discover
rumored missing caverns

and tunnels and ultimately
decipher the purpose

for this massive undertaking.

The scope of secrecy and
the huge presence of SS

lead many to believe
this was intended

to be a fuhrer
command headquarters

for Hitler himself.

- It stands to reason that
if the complex was envisioned

as a fuhrer residence,

that some of these tunnels
might fit those priorities.

You could have had a train
coming through those tunnels.

So they would have had to
be big for that reason.

- [Narrator] Hitler had
many other bunkers.

Could they yield
clues to the mystery

of the Osowka Complex?

- Most of the theories are
that it was the fuhrer bunker,

that it was created
for at Adolf Hitler as

a frontline position to
command the authorities

of the armies in
defense of Germany.

- Albert Speer
wrote, after the war,

that it was supposed to be a
regional administrative center

with a fuhrer headquarters
and industrial facilities.

But people don't
necessarily believe him

because he often was suspected

of trying to throw people off.

- [Narrator] Hitler was
known to have spent much

of his time supervising the
war effort from within bunkers,

such as the Berghof, Wolf's
Lair and Wolf's Lair II.

- There was a desire
for Hitler to be closer

to the front lines.

So it makes sense that the
fuhrer headquarters would

be positioned in places
that had something to do

with the war effort.

As commander of the armed
forces, he moved around.

He tended to move where
there was a battle

or a fighting front.

- The Nazi's stunning military
successes at the start

of the war mean
that Hitler's got

a pretty good working
relationship with his generals.

He trusts them.

But as the war starts
to turn against him,

Hitler becomes
increasingly more paranoid.

Not only does he think his
generals are incompetent

and frequently replaces them,

but he starts to believe that

that actively
plotting against him,

culminating, of course, in
the attempt on his life.

Well, for Hitler, this is
proof that only he and he alone

is the supreme
military commander can
run this operation.

He is quite literally
ordering units

into attack to
stand their ground.

He's issuing orders
that go right down

to captains,
lieutenants, majors.

And we're not just
talking generals.

He's running this war himself.

- His fascination with
fuhrer bunkers is important

because he imagined
himself, at various stages,

to be the military architect
that he always wanted to be.

He thought that he
was the great genius

behind German military strategy.

He was absolutely not.

And also that he would somehow
inspire these heroic defenses

of Germany, particularly
as the war went poorly

by being in places like
the Wroclaw in Poland.

But if you sort of
extrapolate from that

and try to imagine what
these tunnels represent

as a fuhrer bunker, it's
not really consistent.

- [Narrator] There are
noticeable differences

in design between Hitler's
oft used forward HQs

and the Osowka tunnels complex.

- This one is
particularly massive

and seemed to imply
multiple purposes.

- [Narrator] The Berghof
was Hitler's headquarters

in the Bavarian Alps.

Later altered, it became
his vacation home in 1935.

- The Berghof was
also very outlandish.

So it starts out as a
very small place based

on the fact that Hitler had
a vacation property there

and places to store
loot and wine.

And by the end of it,

most of the senior
Nazis had villas there.

- [Narrator] But the layout
of the Berghof doesn't look

at all like the Osowka Complex.

The Wolf's Lair, a two and
a half square mile complex

on the Eastern front consisted

of three concentric
security zones.

It housed some 2,000 people,

including some women
who were required

to sample Hitler's food
to test for poison.

- The Wolf's Lair, which
was also in the East and

was a popular fuhrer
headquarter was the site

of the 1944
Stauffenberg bomb plot.

- [Narrator] Known as
Operation Valkyrie,

it was an attempt by
conspirators to take control

of Germany and
assassinate Hitler.

It failed.

- After that, the security
around Hitler is stepped

up quite a bit, and
it's possible, also,

that some of the more
intricate structures would have

been part of an attempt to make
these places far more secure

to protect Hitler, not
only from being killed

by an enemy plane,
but protecting access

to him so that no enemy
within could get to him.

- [Narrator] Certainly,
that could explain

the complexity of
the Osowka complex.

- Other fuhrer bunkers
are considerably smaller.

They're not anywhere
near the heft or the size

of the scale or the scope
and not as interconnected.

Sufficiently impressive
defenses, I suppose,

but nothing along these lines.

They're not as cavernous,
they're not as massive.

- The main differences
is that mainly,

Wolf Lair is a on surface
structure and all structures

in the complex are
completely underground,

inside the mountains.

- [Narrator] Advances in imaging
technology allow experts

to compare these ruins.

- They can't imagine
you building facilities

that had interconnected railways
and huge ceilings simply

to either have a command
center for the fuhrer

or to protect the fuhrer.

- [Narrator] In addition
to this massive complex,

looking so dissimilar from
Hitler's other traditional

forward HQ's, he
was rarely, if ever,

reported to have
visited this location.

- One would expect that
Hitler would frequently visit

this facility for what, today,
we would call a photo op,

but that wasn't the case.

Hitler did not visit the site
as often as you would expect.

Why; number one, it's secret.

He doesn't want people
to know a lot about it.

And as remarkable as
this structure is,

we need to remember it's
one of dozens and dozens

and dozens of massive
development and
construction projects.

- [Narrator] while the Nazis
destroyed or hid most

of the documentation,
in their haste,

they did leave clues
behind in the forest that

could shed light
on this mystery.

An underground city
is built by the Nazis,

as a defeat for Germany looms.

- There are miles of tunnels
burrowed into the mountainside.

- [Narrator] While explorations
inside the complex attempt

to reveal more hidden spaces,

a new clue is found
in the forest nearby.

The few documents found
specify massive amounts

of concrete were
delivered to the site.

But upon inspection,

only a few piles of
fossilized bags are visible.

- If you're managing a
project of this magnitude,

you know how important it is
to order your material ahead

of time, because nothing
is worse than having all

of the forms ready
to pour concrete

and the concrete isn't there.

So if it was ordered
and it was transferred,

it's expected to be poured.

So where was it poured?

- There are some documents
mentioning that a mound

of concrete should be
spanned in those mountains,

should be somewhere there.

- The amount used in
these tunnel systems

was 360,000 cubic yards.

It's the equivalent of a
cube that's 210 feet on site

or 12 times the amount that went

into building Yankee Stadium.

- The Nazis didn't
make clerical errors.

The concrete was here,
it was sent here,

it was designed
for this location.

- We know from documentation
that this entire tunnel system

was supposed to be supported,
but onsite, it is not.

There's only maybe
10% done right now.

So, they had intended to
do a significant amount

of more work.

- And we do not see, in
the structures, remains,

any sign of this concrete.

- [Narrator] During
the construction of
the Osowka tunnels,

the decision is made
to hand control over

to Organization Todt responsible

for handling vast
construction projects,

such as the Autobahn.

It's unlikely this concrete
would have gone unused.

- Operation Todt was a
part of a massive series

of organizations that managed
concentration camp labor

and managed forced labor
across the Third Reich.

And they were very effective
at getting not only a lot

of labor onto major projects,
but finding the kinds

of labor that was skilled in
various aspects of a build.

- There are rumors
that won't go away

that there are indeed
more tunnels and
more complexes hidden

in the mountainside around
their Osowka Complex.

If more tunnels and underground
chambers were discovered,

it might help piece
together the puzzle.

- [Narrator] Today, initial
investigations reveal

multiple intentionally
collapsed and buried entrances

and shafts, potentially
concealing massive sections

of the Osowka Complex.

- Presumably, the tunnels
would have been dangerous.

Some of them would
have been destroyed

by the retreating Wehrmacht.

Some of them were walled
in by the Soviets,

which leads to a whole
series of other questions.

- Why would the
Nazis, after the war,

have gone to all the trouble
of destroying these tunnels

to keep this place a secret?

- I'm incredulous that
they would destroy tunnels

if there was any possibility
of finding things

in those tunnels.

- Documents state there
should be some more tunnels.

There's still a lot of
hope that there must

be something more to detect.

- [Narrator] Penetrating igneous
rock is a difficult task,

but modern technology
might shed some light

on the tunnel makeup.

- The FLIR camera
show us difference

between comparator
in different spaces.

It's very useful
in a close space.

Now is in the camera
some empty space,

which have different
temperature.

- [Narrator] Another method to
detect underground structures

is ground penetrating radar.

- Ground penetrating radar
is similar to normal radar

that we use above ground.

You emit a series of
electromagnetic waves down

into the ground, which then
bounce back off anything

that's beneath your feet.

And it's used to
show you if there

are different materials
buried in the ground,

and it can tell you
how deep down they are.

So it can be used to detect
things like pipe work or cables.

It'll often pick up
lumps of concrete

or, occasionally, big voids.

- If we have a tunnel and
the tunnel is blocked,

we trying to detect
what is behind,

but we can do it only
from the surface.

For sure, they could be
below, but in each site,

in which direction.

So we do it sometimes blindly.

- [Narrator] Can
Piotr's investigation
involving GPR reveal

some truth to the
tunnel's mystery?

- We've already
made, many times,

such a scanning in this place
and nothing special happened.

- [Narrator] But this time,
something different.

- Surprisingly, we
have a huge anomaly.

- [Narrator] Though he
and others have thought

they had scanned this
place many times,

an opening has been detected
below the cavern floor.

- Everyone want to believe
that below those structures

we know there are other
which are unknown.

We hope that they still exist.

- [Narrator] Could this void be
one

of the lost Osowka tunnels?

A team is using ground
penetrating radar

in the Osowka tunnels,

hoping to find new
clues to the complex.

Piotr has been exploring
these tunnels for years

and has run several
GPR scans in that time,

mostly with no results, but
this time, he detects something.

- We was scanned by GPR system.

Surprisingly, in this moment,
we have a huge anomaly.

I cannot explain
it, but definitely,

we have some empty space below.

- [Narrator] Additional scans
confirm a large void below

what is thought to be the
bottom of the complex.

- I think a lot of
geologists would probably

be quite excited
discovering a void

that they didn't
already know about,

like a tunnel or a cave.

So for example, if you
were in these tunnels

using ground penetrating
radar and you you'd mapped all

the tunnels out,

but you found a void beneath
you that you didn't know about,

that would spark some interest.

- To definitely
check what is below,

we would have to prepare
drilling to have final proof

that there is something below.

The main thing that
people still looking for

are missing tunnels
because we all believe

that there is still more
finished tunnels in the area.

- Really, what the goal
would be to figure out how

to map that system in its
entirety and piece together

what the various parts of
it were gonna be used for.

- [Narrator] While experts
continue to piece together

the tunnel system to
get a bigger picture

of this grand complex,

experts look to the timeline
of the war for further clues.

- While the war in the East
initially goes very well

and the Germans advance,

the tide turns over
the course of 1942.

- The Allied invasion at
Normandy in June, 1944,

precarious as it
was, spells the end.

- [Deborah] Soviets and the
Western allies had not broken

the Alliance that so many
Germans had been hoping.

- With the Soviets
advancing at pace,

driving the Germans back,

it does seem odd
that the Nazis would

then put so much effort
into constructing

this secret complex.

- Why they're still pouring
so much energy into it

when it's becoming
increasingly clear

that they're going
to lose the war.

And it also causes
us to ask questions

about what they then thought
they might use it for

in the event that
the war was lost.

- [Narrator] Perhaps these
tunnels were created

to house something truly unique.

- We know that the
Germans started

moving important
things underground.

- [Expert] Could it have been

for storing all their valuables?

- The Nazis envisioned
themselves to be the defender

of European culture, not
just of Germanic culture.

These were guys that had
looted Europe since 1939,

millions of pieces of
artwork, sculpture, paintings,

you know, you name it.

- [Narrator] As the
pendulum of war swings

in favor of the Allies, the
Nazis frantically search

for places to hide
stolen artwork.

- This is the ideal place
to hide all the things

that you've been stealing
for years and years.

We're talking about billions
of dollars of artwork.

Nobody would have known
what was under here.

- And also, they were
people that wanted

to gain tremendous
personal wealth.

So there is a lot of
substantiation to the fact

that these facilities may have
been designed to harbor some

of these artifacts and lots
of that artwork has never

been accounted for.

You're left with big, huge
chambers that conceivably

could have been used for loot
that Germans took from Europe.

- [Narrator] But some experts
doubt the suitability

of the conditions for storage
of delicate valuables.

- Tunnels aren't
great for artwork.

They're high humidity.

Older pieces of art don't do
well in humid environments.

They really do need careful
temperature control.

So it's really not an
ideal place for artifacts.

- [Narrator] If not
for stolen treasure,

some researchers look to
the extremely high presence

of the SS to explain the need

for such a huge
scope and secrecy.

- Were people trying to think

of exit plans when it
became increasingly clear

that the Germans were
gonna lose the war?

Absolutely, they were.

- There are theories that
the Nazis had planned

for one last stand,
possibly to come into action

well after the war had finished.

- [Narrator] One of the
rumored plans involves

a highly secret elite
unit dedicated to carrying

on the fight no matter the odds.

- If you are looking for
a place to secretly hide

and store both
troops and equipment,

you can't deny that the
secrecy and isolation

of the Owl Mountains
would have been

the perfect place to do that.

- The system is built
in a place that had once

been fundamentally
part of Germany.

Did they envision that
they were going to lose

this territory altogether,

depending on the
outcome of the war?

Probably not.

Hitler had ordered,
in certain places,

the Germans not to surrender

and to essentially
create fortresses

that they were
supposed to hold out in

as the Red Army came through.

- Strictly speaking, from
a defensive position,

it would make sense
to hold yourself

up in the Owl Mountains,
relatively remote,

it's shrouded all the time

and hard to navigate in a
kind of dark forest way.

But more importantly,

you're shoring yourself up
within the frame of a mountain

and that affords you some degree
of defense against weapons

of all sorts, right, against
artillery and against bombing.

- If we see the wrench
of this complexes,

how huge it was, in fact,

it could protect against
even not conventional weapon,

but also against
the nuclear weapon.

- The elaborate nature
of the systems underneath

with interconnected,
everything, you know,

that would be consistent
with a last stand.

But it really does
look like a place

where you're pooling all
of the last resources

that you have and particularly
the ones that you think,

in your madness towards
the end of the war,

might tilt the balance.

- You're not talking about
one or two people underground.

You're talking about
thousands of people.

Therefore, the facility itself
is only a small fraction

of the overall project.

There have to be piping,

there has to be
tunnels that lead

in all directions to come
above ground for ventilation.

There has to be fan systems.

There has to be an
electric generator that

is supplying a lot
of these systems.

So this was an enormous

and complicated
construction project.

- We know that there were
Nazi German leaders who

were encouraging the
Germans to escape

into the mountains and
carry on the guerrilla fight

against whichever
enemy were there

and keep the Nazi flame alive.

Maybe this all was
gonna be a part of this.

After all, the woods around it
and the tunnels underneath it

make the perfect hiding ground
for whatever continuation

these mad men wanted to have
happen as the war ended.

- It's a heck of
a place to hold up

what's left of your army
and fight to the end.

That, to me, is consistent
with a lot of the Nazi ideology

throughout the war as well as

the senior command
right to the end.

- There's reason and purpose
for these large spaces

to be filled with something,
populated, like a city, almost.

- [Narrator] Whispers
of a fanatical

and secretive unit persist.

Could the complex have
been built as part

of a secret unit known as
the Werewolves Operation?

As Hitler orchestrates
his plans to keep fighting

in the face of an
increasingly grim outlook,

signs point to the
Osowka tunnels being

the site of a Nazi last stand.

Reports of an elite

and shadowy fighting
force intrigue experts.

- The SS wasn't a
singular organization.

It never was.

It had multiple
units, I should say,

or departments within it.

And it rather infamously
devised special forces

within its own ranks.

- [Narrator] Operation Werewolf
was

a Nazi last ditch attempt
to create secret units

to harass the advancing Allies

and Soviets behind enemy lines.

- The SS Werewolves
are sort of infamous,

specially trained defenders
of the most sacred places,

sort of the ultra hardcore of
the hardcore Nazis as it were,

of the SS in particular.

- [Narrator] But whispers
persist

of the plan going much deeper.

- The rumor was that the
Werewolves were a branch

of the SS who were commissioned

with staying around in
the region after the war,

engaging in a kind
of a partisan fight

to destabilize the region
even after the war was lost,

and also destroy any information
related to the project,

to wreak havoc in
the countryside

and to protect the secrets
of the tunnel system.

- In that light, the
Werewolves are kind of

the ultra fanatics
that would be commanded

by the SS and report
exclusively to the SS.

So this is somewhat of a legend,

that they were all
dedicated past 1945.

- [Narrator] On April 1st, 1945,

the first array broadcast
plays across radio stations,

starting with a howling wolf.

A hunting song would
begin whose lyrics were

my werewolf teeth
bite the enemy,

and then he's done,
and then he's gone.

The broadcast that followed
ordered Germans to stand

their ground against Allied
armies or face enslavement.

A chilling message followed.

Any Germans, whatever
his profession or class,

who puts himself at the
service of the enemy

and collaborates
with him will feel

the effect of a revenging hand.

A single motto remains
for us, conquer or die.

- Adolf Hitler's
stuck in this bunker,

never to emerge alive again.

And yet, it's rumored that
werewolf operatives were sent

to this region to continue on.

- The notion that
there were stray bands

of former SS roaming the
countryside and terrorizing

the population obviously struck
fear and horror in the minds

of residents and became part
of the mythos of this area

that the Werewolves were
fighting a rear guard action

to protect the secrets
of the Third Reich

after the official end
of the war in 1945.

- I've never seen
the documents to say,

hey, go to the Owl
Mountains and fight until

the end of the days.

But I think it's a
reasonable assumption

that they were told that.

- In certain factions of the SS,

there were very fanatic
members of that organization

who would have done
just about anything

to protect the Third Reich
that they so truly believed in.

- It kind of makes sense
that the die hard Nazis

in the higher echelons
thought that this would be

a logical place for
one last hurrah.

- [Narrator] The Nazis furiously
build this underground city

as their defeat looms.

- For all intents and purposes,

it was over the moment that

the Soviets broke
out of Stalingrad.

- Surely, at that
point in the war,

it would have been
all hands to the pump

to be on the offensive
at the front line.

- [Narrator] Closing in on
Germany,

the Red Army pushes
into the Owl Mountains,

only to discover
a shocking network

of vast tunnels linked to even
more mysterious structures

in the surrounding forest.

- It's really almost
something truly out

of a science fiction movie.

- [Narrator] Not only was the
complex itself sealed off

from the world, the
fleeing Nazis made sure

to eradicate any documents
left over pertaining

to its construction.

- There must've been
a mass burning event

in the waning days of the war.

We know from other sites
that that is indeed the case

and that Hitler was always
telling his advisors when

they were moving from one
place to another to burn papers

if they thought they
wouldn't be coming back.

In the bunker, he's asking
people to burn his papers

so that they won't
fall into Soviet hands.

So one suspects that there
was a concerted and probably

a sustained effort to burn
all available evidence

about what the
tunnels were used for,

a very deliberate policy under
that scorched earth directive

to destroy information that
could reveal the grand plans

for any installation or
any particular location.

They would have had
enough time, I think,

to get rid of quite a bit before

the Red Army actually arrived.

- [Narrator] Given the resources
the Nazis had poured

into this complex up until

the final moments
of the Third Reich,

modern day investigations have
revealed sabotage entrances

and collapsed caverns.

What could have happened
in the final moments

of the Osowka Complex?

- Some of them would
have been destroyed

by the retreating Wehrmacht.

It appears the Soviets also
blew up some of the tunnels

or the tunnels were blown
up when they got there.

So there's a bit of a puzzlement

about what actually happened
inside those tunnels

in the waning days of the war.

- Many people harbor all
sorts of fantastical ideas

about what the
Russians found in it.

- Because it was the Soviets
who overran this area in 1945,

much of the information that
they potentially uncovered

was taken back to
the Soviet Union.

And because of the Cold War,

it was never
disseminated in the West.

- [Narrator] Was it the Nazis
who desperately needed

to bury the secrets
of this complex?

Or did the Soviets discover
something in the tunnels

and decide to prevent
access to them forever?

- Visiting these Nazi
bunkers and secret tunnels

is a chilling and
haunting experience.

Many of them are in
pristine condition.

You can almost feel,
you can almost hear,

you can almost
sense the Werhmacht,

the soldiers marching through.

It's unlike visiting
other historic sites,

which you can
appreciate the history,

you can appreciate
the architecture.

But when visiting any Nazi site,

one is reminded of the
evil that was happening

at that facility.

- But the fact
that we can't see,

or haven't discovered the
real extent of this system,

that's the biggest mystery.

What else is under there?

What might we find if we're
able to explore deeper?

- All kinds of new stuff
continues to come to light,

even things as simple
as diaries that soldiers

on the Eastern front
wrote, but also,

important papers that were
not destroyed in time.

And that's why we have
these stray pieces

and the job of scholars
and historians,

their job is to put all of
these little bits and pieces

into some kind of
coherent narrative

that may help us
make broader sense

of a project of this scale.

- The reality is is
that there are many,

many more stories that
we're still questioning.

And we probably will for a
very long period of time.

- Truth is layered, but
by combing the archives,

and putting together evidence
in a responsible way,

we can approximate a
truth of what the plans

for that set of structures.

- We know much, much more
than we knew 50 years ago,

but we can only imagine the
final view and the dimension

of all those complexes
if that will be finished.

- [Narrator] Evidence mounts,
suggesting the Osowka tunnel

was simply one part of a
much larger super complex

throughout the Owl Mountains.

And continued
investigations promise

to uncover new secrets
locked in the walls

of this underground city.

[dramatic music]