ERIC GELLER (VOICEOVER):
Dig beneath the fancy hotels and modern construction
sites and you'll see Hungary's capital
city of Budapest is hiding a colossal
underground kingdom. It's astounding. It's amazing. This thing still works. This is an amazing labyrinth. ERIC GELLER (VOICEOVER): A
dark world of ancient caves and subterranean seas. This feels like we are in
the devil's layer right here. [laughs] Yes. ERIC GELLER (VOICEOVER):
From the invading Mongols, the remains of the Romans,
the Turkish takeover, and the bloody battles
of World War II, Budapest has seen over
two millennia of war and destruction. But while most cities were
building castles to the sky, Budapest was engineering its
kingdom in the underworld. This is the cave hospital. Probably nine out of ten local
people have no idea about. ERIC GELLER (VOICEOVER): With
the help of expert guides, we'll find the narrow
passages and unlock the doors that hide the
secrets to constructing a city of caves. And he's found something
right there right now. ERIC GELLER (VOICEOVER): We're
peeling back the layers of time to uncover Budapest-- the subterranean city of caves. [music playing] In the heart of Eastern Europe
sits a city like no other, a city where nearly two million
people live directly on top of a super network of
20-million-year-old caves. I'm Eric Geller. I'm in Budapest, Hungary. And for nearly 2000 years,
this was a city under siege. It was ruled by the
Romans and the Ottomans. It was sacked by the
Huns and the Mongols. And it was nearly destroyed
by the fierce battles of the Second World War. Now everywhere you look,
you can see the remains of this turbulent past. But there's another layer of
history here, a secret world that's been brewing
underneath these streets since the dawn of time. ERIC GELLER (VOICEOVER): The
story of Budapest's underworld goes back 20 million years,
when the caves beneath the city were first carved
out by thermal waters from deep inside the Earth. No other capital
city in the world sits on such a vast system,
one whose strong walls literally hold up the city and
whose dark unexplored recesses still hold the clues to
Budapest's turbulent past. Today's Budapest is the capital
of the Republic of Hungary. It's a dynamic city
of 1.8 million, full of bubbling bathhouses,
bustling markets, and massive bridges
crossing the Danube. Just 17 years after
the fall of communism, the city is growing
at breakneck speed. And with the Iron
Curtain lifted, the caves that helped to
create the vibrant city above can finally be explored. The caves in Budapest are found
on the Buda side of the city. Once two separate
cities of Buda and Pest, Budapest was united
as one in 1873. Pest sat on the flat
side east of the Danube. And Buda was the hilly
cave-filled region on the west banks. Together they create the eighth
largest city in the European Union. But what went on in the cave
systems beneath the Buda Hills? I was about to enter an
underworld once inhabited by cavemen full of trash
from the Turks and the Romans and where some of the bloodiest
battles of World War II took place. I'd start my journey down at
the Palvolgy-Matyashegy Cave System. This system was discovered
only 100 years ago. Today it's a playground
for urban explorers. Szilard? Hi, Eric. Welcome to the
Palvolgy-Matyashegy cave system.
- Thank you. That's your clothes. You can take home. Oh, excellent. Gonna get me geared
up here, huh? ERIC GELLER (VOICEOVER): I
met up with Szilard Regos, an urban cave explorer. Oh, yeah, baby. ERIC GELLER
(VOICEOVER): Szilard was going to show me one
of the longest cave systems in Budapest. So-- [horn honking] --we're walking in the
middle of the street, right? Yeah. There's houses there,
apartment buildings. This is right in the
middle of Budapest. - Yes.
- And there's a cave over here? Yes. ERIC GELLER (VOICEOVER):
There are over 170 known caves beneath Budapest formed by
the thermal waters surging beneath its soil. The Palvolgy-Matyashegy
cave system is one of the newly discovered
systems in the city. It was first mapped out
in the early 1900s when the ground collapsed beneath
a goat grazing up above. Residents began to explore
the labyrinth below. And today the entire system
is almost 12 miles long. OK, just open the door. OK. When you go down, [inaudible]. OK, excellent. [inaudible] We've already descended
about 20 or 30 feet here. And we've got to
go through a very-- looks like a narrow
passage right here. It's, like, just a playground. - OK, let's go.
- Lay down. - Let's have some fun.
- And move in. And we'll slide down. That looked easier the
way he did it, right? All right, as always,
if I die, my last words are tell my mother I love her. ERIC GELLER (VOICEOVER): The
cave snaked for miles, hardly something I expected to find
beneath the capital city. Oh, I shouldn't have
had all that goulash. ERIC GELLER (VOICEOVER): We
had already descended 50 feet, and the cave kept going deeper. At their deepest point, the
Palvolgy-Matyashegy caves are 300 feet
beneath the surface. So above us right now, there
is a house right above us or the road above us? Yes. Cars passing above us? Yeah, it have. So show me where
we are right now. Where did we enter? We entered here and went
down, we slided down on this way and arrived to the great hall. ERIC GELLER (VOICEOVER): Szilard
told me that this system isn't the only one. There could be hundreds more
waiting beneath the streets to be explored. But finding them
isn't an easy task. Because as the city
continues to grow on top, accessing these
virgin systems becomes more and more difficult. What is that? That's a fossil. Oh, look, we
have a fossil here. It looks like a
fossilized shell. It's a part of a sea urchin. ERIC GELLER
(VOICEOVER): But what was a fossilized sea urchin
doing 50 feet beneath Budapest? Amazingly, millions
of years ago I wouldn't be standing
in a dry cave, but swimming in the Pannon
Lake, a large brackish lake that mysteriously dried up sometime
in the last 10,000 years. Hungary and many of the
surrounding countries in the region were once
covered by the Pannon. The fossil I had found
was from that time. And here's what happened next. Over millions of years,
sediment from the sea, including dead creatures,
formed layers of dolomite and limestone over a mile deep. The Budapest region
emerged as an island. Eventually, the water
receded and tectonic shifts in the earth caused
the hills of Buda to rise above the Pest
side at the fault line where the Danube river
still runs today. So now Buda was a
hilly landscape. But how did the caves form? It all started when the
same tectonic shifts that gave the city its hills
left faults and fissures that trap enormous pockets
of water or aquifers. Beginning about two
million years ago, this water rich in hydrogen
sulfide and carbon dioxide was bubbling just
below the surface. When rainwater would percolate
down through the limestone, it mixed with the
geothermal water and created a
mineral-rich fluid. The thermal waters began to
dissolve the stone and course through the canals, creating
chambers and tunnels. Over two million years later,
the water level has dropped, but the caves it
created still remain. Today, millions of years of
history are hidden down there. And if I wanted to
find them, I had to get beneath the district
of the Castle Hill. Castle hill is one of the oldest
neighborhoods in the city, and beneath it sits one of
the world's longest limestone caves system. I went to the Budapest
University of Technology and Economics and met with Dr.
Tamas Mezos, a professor who had studied the parallel world
of caves underneath his city. Beneath the streets of
the Castle Hill district, there is another city. That is true. We know that we have a very
important and huge cave system, such a cave system
nowhere exists. ERIC GELLER (VOICEOVER):
The Castle Hill cave system was rediscovered in 1818
when a horse actually fell through the ground. Local government decided
to investigate further. A few years later, the city
finished a survey of the caves beneath the streets and made
an extensive map of the system. But around the turn of the
century, the map was lost. Even today, no one knows
where that map went. It was really very
interesting that practically from the 9th to
the 13th century, there was a parallel city. It is a pity story that
geological survey was lost. It is sure that we have
to resurvey it again. Because that cave system
is a part of our heritage. ERIC GELLER (VOICEOVER): It's
a heritage shrouded in secrecy that's been mostly forgotten
and sealed up in the caves beneath Castle Hill. And I've been granted
special access to go down. Today the streets of Budapest
are packed with shoppers and vendors, tourists and
businessmen, people going about their daily lives. Once a military
outpost for the Romans, the city has since boomed
into a major metropolis. But long before skyscrapers were
constructed along the Danube, Budapest was booming
below ground. ERIC GELLER (VOICEOVER): There
are miles of caves snaking beneath Budapest. But it's within
the system of caves beneath Castle Hill where
the history of this city first began. Walking through them is like
walking through a time machine all the way back
into the ice age. The caves first began to
take on a life of their own in the 13th century when the
Hungarian kingdom was situated on the flat banks of the Danube. But this location left
them exposed and allowed invading Mongols to sweep
through and slaughter nearly half the population. Entire villages were wiped out
and the kingdom was in ruins. The Hungarian ruler at
the time was King Bela IV. Today he's known for
rebuilding the kingdom after the brutal
barbarian slaughter. His first decision was to move
the entire kingdom 200 feet up into the hills of Buda. It was a strategic
move on his part, for he knew of the caves and
wells that existed there. He now had the protection
he was looking for, both above and below the ground. The 300 homes in medieval Buda
sat on top of 285 wells fed by thermal springs. That meant just beneath
their basements, most citizens had access
to the first level of caves and they put them to good use. Winding for miles
throughout the city, the caves were no longer
just storage areas. They literally became
a major thoroughfare beneath the streets. But that didn't last long. Homeowners began to
wall off sections beneath their basements,
closing off the passages. Slowly, the great
labyrinth became a series of individual cellars. Today, underneath most
houses on Castle Hill, you'll find access into this
sealed-off time capsule. First, there's the surface
level of the house, next, the basements
of each home, then arched medieval
cellars used by the Turks, and finally, the natural
cave level beneath that. And I was about to be one
of the few allowed down. [music playing] [train bell ringing] Zoltan Bene is a
retired civil engineer for the city of Budapest. He brought along
Adena to translate. Zoltan knows this hidden system
like the back of his hand. He's the one they call in
the middle of the night when the occasional daring
citizen finds his way in and can't get out. [music playing] This is an amazing labyrinth. I mean, I'm looking right here,
I'm seeing a corridor that way, one that way. They're everywhere I look. And look at this, we see
the natural rock right here. We see old field stones
and contemporary. ERIC GELLER (VOICEOVER):
Unlike the more remote Palvolgy-Matyashegy
cave system, this one had been inhabited by nearly
every generation of Castle Hill residents since the Romans. Today, it's hard to tell what's
natural and what's man-made. So each one of
these compartments belongs to another house. Oh, look, and here we see some--
it looks like very crude steps. ERIC GELLER (VOICEOVER):
This stairwell was one of dozens in
the cave system that led to the medieval homes and
buildings sitting up above and is another example
of the layers of history beneath the streets. In these very rooms, residents
used to hide their valuables from tax collectors. You could hollow out an
area, place your valuables or your food reserves, and
then put some more stone on top of it. And then when the taxman
comes or the invader comes, they're certainly
not going to find it. ERIC GELLER (VOICEOVER):
There was a makeshift prison used to hold the town drunks. We can imagine somebody
might have been chained. That's it, exactly? That's it exactly, yeah. Not a good place to be. You probably
learned your lesson. You probably stopped
fighting and drinking. ERIC GELLER (VOICEOVER):
There were fossils from when the caves were formed. I see, this as a bone. It's a fossilized
bone right here. Yeah, that's a bone. ERIC GELLER (VOICEOVER):
And even remnants of a time most Budapest
residents would rather forget. I'm right now standing in
a World War II disinfection chamber. And I should probably
leave this room before I catch another
infection from the underworld. ERIC GELLER (VOICEOVER):
Walking beneath the streets, it was easy to forget you were
in the middle of a capital city. But occasionally,
there were reminders. So there was a palace
above us at one point. And this was an exit. ERIC GELLER (VOICEOVER):
A Hungarian palace built in the Middle
Ages once sat directly on top of this system. The chambers I was
walking through would most likely have been
used for royal storage. But this palace was one
of the many destroyed during the course of
Budapest's violent history. And today, a busy bus
station sits on top. A palace, a bus station, homes
and hotels put a lot of weight on the fragile caves down
below, but none as much as Castle Hill's most
iconic building-- the famous 800-year-old
Matthias Church. Having renovated the church over
seven times in eight centuries, Budapest engineers knew
they couldn't keep building without retrofitting
the caves below. If I just start
pulling around up here, you can see that this
is just really porous. So what they have
to do occasionally is reinforce this whole
structure with pillars, with stonework. They probably close off
portions of this cave, otherwise Matthias church
would be where I am right now. ERIC GELLER (VOICEOVER):
And falling into the caves isn't unheard of. The house above
this place cracked. The house above
this place cracked? And they had to reinforce it. Yeah, that's right. I see. And I think their plumbing
up above cracked, too, because it's coming
around down on us. ERIC GELLER (VOICEOVER): Pillars
from throughout the centuries are littered throughout
the caves below. But today, the pressure on the
caves is greater than ever. And it's not the
buildings, but the buses that have caused the most
problems in the 21st century. Today's building materials
of steel and concrete are generally much lighter than
the heavy stone predominantly used during medieval times. So the problem
doesn't necessarily come from the added weight
of the modern buildings, but from the buses that
zip around the Castle Hill district. Double-decker tour buses can
weigh as much as 10 tons. And as they move
along the street, they send a shock wave
through the limestone below. The constant vibration
weakens the existing faults in the caves and
can cause collapse. To prevent further
damage, tour buses are no longer allowed to drive
the streets of Castle Hill. Instead, special mini
buses have been introduced for public transport. But there's no way of protecting
the caves from mother nature. The limestone of the
caves is especially susceptible to erosion
from acid rain, an epidemic in any large city. So as the city above
gets more polluted and acid rain continues
to seep into the caves below, over time, the
city's limestone foundation can slowly wither away if
the caves aren't fortified. Throughout history the caves
may have been problematic for structural engineers. But during the intense
bombings of World War II, they were among the only parts
of the city that survived. 80% of Castle Hill
was destroyed, but the caves
allowed the military to continue to
operate underground. During the Second
World War, Hungary was allied with Nazi Germany. In preparation for a
war inside the city, the Axis armies
reconnected the cave system by knocking down many of
the cellar walls erected by private homeowners. They used the space as a way
to move troops from one side of the city to another. And they used this room as
a military headquarters. They added water and
electricity, bathrooms and air filters, all right
beneath the city streets. This was a siren. So if we had an air
raid or we needed to position our soldiers,
we would crank this. Now, clearly it would have
been louder than that. It really puts you in touch
with what this space was used for during wartime. ERIC GELLER (VOICEOVER): From
wartime during the Middle Ages to the battle for Budapest
during World War II, generation after generation has made use
of the million-year-old caves beneath Castle Hill. And after spending most
of the 20th century shrouded in secrecy,
today's residents are just beginning to explore
the parallel world that's been sealed off beneath their feet. This building is
one of only a few that survived the
Russian siege of Budapest during World War II. It was a two-month battle. Fierce bombings destroyed over
70% of the city's buildings and inflicted heavy casualties. Completely surrounded, the
Hungarian and German armies had only one place to retreat-- the underground. ERIC GELLER (VOICEOVER):
The city of Budapest has been under siege as many
as 32 times in its history. But none was more destructive
than the siege of World War II. Just before New
Year's Eve 1944, bombs began to rain down on the city. As they had done for
nearly a millennium, both the residents
and the military retreated into the
caves of Castle Hill. Civilians used the cave
cellars beneath their homes as bomb shelters. The military used the cave
system as their headquarters. And as casualties
began to mount, they also used it as a hospital. Many locals have heard a rumor
about a top secret World War II hospital inside the
caves, but few have seen it and no maps or blueprints exist. I met with Andrea
Makkay, a guide who knows all that is secret
about Budapest's Castle Hill district.
- Hello. - Hi, Eric.
- I'm Eric. Hi, Eric. How are you? Fine, thank you. ERIC GELLER (VOICEOVER): We
were given special access to go where few had
ever gone before. So this is actually a place
that probably nine out of ten local people have no idea about. It's a very secret place. [music playing] Look at this. It's astounding. This is the cave hospital. Starting from the
middle of the '40s, they made it into a hospital
for the obvious reason that the war was on the way. ERIC GELLER (VOICEOVER):
The Hungarian generals knew about the hidden cave
system beneath the city and used it to their advantage. Knowing full well the Buda Hills
would be a key battleground, they built their headquarters in
a secret hospital underground. ANDREA MAKKAY: The structure is
30 meters underneath the ground of the Castle district. More or less under
Matthias church. ERIC GELLER (VOICEOVER): I had
just come from the labyrinth of natural caves
beneath Matthias Church and saw no signs of the
hospital, evidence of just how top secret its location was. The hospital's entrance was
meant to be extremely discreet. So instead of just digging down,
the military engineers actually bore a hole through the
north side of Castle Hill, knowing the caves were close by. After connecting to
the natural cave system and converting the
tunnels into the hospital, engineers needed to make sure
the new structure could support the weight from up above. At nearly 60 feet
beneath the ground, there's almost 6,500 pounds
of pressure per square foot. The cylindrical shape of the
tunneled halls of the hospital distributes the weight of the
soil pressing down on its sides and forces it back
into the dirt. Engineers had succeeded in
breaking through to the caves and retrofitted them into
a top-secret subterranean hospital that stretched for
over a mile beneath the city. Because the hospital simply
follows the natural path of the caves, the
architects had to make the most of the
oddly-shaped rooms in order to create a
fully functional hospital. Now, I see that there is this
slope, and there is odd curves. That's because that this was a
part of the natural cave system originally.
- Yes, exactly. So it follows the natural
line of the cave system. So it this very
long, very extensive. It has all together the five
wards, the operating room, the emergency room, and
also the service facility. ERIC GELLER (VOICEOVER): While
the hospital could service up to 200 patients
at a time, there were 79,000 troops who stayed
in Buda to fight the Russians. What were the conditions
like during World War II inside of this hospital? Well, initially the hospital
had the capacity of 200 beds. But by the end of 1945, there
were more than 600 people here. The majority of
them were soldiers, but also there were civilians. Most of them were
very badly injured. So people were brought down
here, as you can imagine, since the hospital
didn't have its own water supply or ventilation, the
conditions were just terrible because there was nothing
to stop infection, the spreading of germs. And of course, many people died. ERIC GELLER (VOICEOVER): Lack
of ventilation and damp air are far from ideal
hospital conditions. But the cave hospital's
secret location, its position deep in the ground, and
the strong limestone rocks surrounding it made it
practically bomb proof. But it wasn't long before
the Soviets discovered this secret cave
hospital and the wounded were like sitting ducks. The Soviet troops
found this secret place. They had no idea about
this up until that point. They came in here
and they actually used a special liquid guns
to kill everyone they found. So it was a real massacre. ERIC GELLER (VOICEOVER):
After the war, the decimated city was
left in Soviet control. The hospital was closed down. Soon, Hungary became a communist
nation behind the Iron Curtain. And after the 1960s, the
threat of nuclear attack compelled the
Hungarian government to retrofit the old hospital
into a fallout shelter. And here you can see this huge
ventilation and filter system. And you could see they were
really prepared for something horrendous to happen here. Now, this was never used. No, because nothing
happened in the '60s. So thank god, it
didn't have to be used. There is no atomic
threat nowadays. But they still turn this
ventilation and filter system on every day in order
to prevent the damp air to damage the whole facility. If you hit a switch,
we could turn this on right now to see if the
filtration system works. Yes, yes, it's possible. Will you try that? Will you turn it on for me now? Sure, sure. Excellent. We're going. We're going. All right, so this
filtration system is working. You can see there's
fan belts pulling this. There's a motor. But these are drawing air. And you can see, they're
coming in off of here. And it leads to each one
of these filter pumps. And it's humming along
pretty good right now. It's amazing. This thing still works. And there would be a lot of
communists still alive right now. ERIC GELLER (VOICEOVER):
Throughout the corridors, wards, and surgery rooms, there
are supplies from the Cold War era stored here in case of a
massive attack on the city. Look at how
well-stocked this is. We have gas masks and canisters. And these are in pristine shape. A little morphine kit in here. Look, we see some goggles. Hello, take me to your leader. All right, hit the
button, zap me. [inaudible] If it was good enough
for the Cold War, it's good enough for me. ERIC GELLER (VOICEOVER):
Today, just like 60 years ago, most residents have no idea
this cave hospital exists. But this half natural,
half man-made structure is a constant reminder of some
of the city's darkest days. I had explored the caves that
had provided this city shelter for millions of years. But there was something
even deeper and older that was hiding beneath
the streets of Budapest. It was a world of water
that brought the Romans to this city. And I was on a mission
to find its source. Budapest is the only
capital city in the world with over 118
natural hot springs full of mineral-rich water
ranging from 70 to 170 degrees Fahrenheit. Today the city is
nicknamed the city of spas. And public bathing
is a deep-seated part of the culture. Bathing is actually
subsidized by the government for its healing powers. And people from
all over the world come here to be cured of
ailments, such as arthritis and rheumatism. The bathing culture in
Budapest started in 89 AD with the Romans. They called their city Aquincum,
which means "good water" in Latin. And the ruins of their Thermae
Maiores, one of the largest bath complexes in Europe
sits along the side of a major thoroughfare. The Turks kept the
bathing tradition alive when they conquered in 1526,
building even more baths and accessing the very same
springs the Romans had. But one spring in Budapest
is the most legendary and shrouded in mystery. Named after a hermit monk that
once allegedly used it to heal the sick, the spring of
St. Ivan is buried directly beneath Budapest's most
famous public bathhouse-- Gellert Bath. But why was St. Ivan forced to
heal in secret when the Romans and Turks could build
architectural masterpieces for bathing above the ground? When Budapest turned
from a pagan empire to a Christian one in 1000 AD,
its baths fell out of favor. Public bathing was
considered a disgrace. So legend has it,
St. Ivan created a subterranean sanctuary to
continue to heal the sick. But was this legend true? I'd have to go deep beneath
the baths to find out. Mr. Balazs? Yes, I am. Good morning, sir.
- Good morning. - Welcome.
- Thank you for meeting me. Welcome, you. ERIC GELLER (VOICEOVER): I met
with Laurent Balazs manager of the Gellert Baths. It feels like I just
stepped into 1920 right now. I mean, look at the vaulted
ceilings, that huge dome and the stained
glass everywhere. Everywhere you look, it's
very ornate, very beautiful. This looks like a
palace for kings. ERIC GELLER (VOICEOVER): The
Gellert Bath was built in 1918. But what it sits on
top of dates back to the beginnings of Budapest. This place originally
from the Romans more than 2,000 years ago. And the Romans used
first this spring. This spring was a
very special spring. It is a lake about
the diameter 20 meter. ERIC GELLER (VOICEOVER):
Just beneath our feet was a 65-foot ancient
spring-fed lake used by both the Romans and later the Turks
and is allegedly the spring of St. Ivan himself. Now, we're going
to the underworld. ERIC GELLER (VOICEOVER): Laurent
was taking me to the off limits sections of the bath where
I could see firsthand this legendary spring. We are now at the
gate of the old world. The official name
gate of the hell. The gate of hell? You'll be very surprised. ERIC GELLER
(VOICEOVER): The gate of hell is actually
an old tunnel that snakes beneath the
center of Gellert square. It's been requested that
I remove my jacket before I go down. So it must be very
informal down in hell. ERIC GELLER (VOICEOVER):
The natural spring or lake at the bottom keeps the
tunnel at a balmy 100 degrees. And you can feel
hell as I walk in here. It was about 80 degrees outside. And as I walk in here,
it's now ramped it up another five or six degrees. And even warmer, oh, man. This is hot. Now, we're getting warm. ERIC GELLER (VOICEOVER): The
water was over 100 degrees. And the heat hit me
like a ton of bricks as I followed Laurent
to its source. It's the tram. That's not the devil, right? - No, no.
- That's not the devil roaring. There's a tram. Yes. And I can actually feel cool
air coming down from the tram. And it actually feels good. But now we're going to descend
into the bowels of hell, I'm guessing. Ah. Oh, you're hit by the heat. This is amazing. This is the original source
of the Gellert springs. Yes. This feels like we are in
the devil's layer right here. Yes. This is hot. If you want to try the
water, here possible. Oh, I see. I see, so I can go
down even further. Yes. So this is St.
Ivan's healing water. ERIC GELLER (VOICEOVER): Over
1,000 years ago in St. Ivan's time, I would have been
standing at street level. Today, the ground
level of Gellert square has risen over 50 feet. That means just the
soil alone is putting over 5,000 pounds of pressure
per square foot on this room. So how was that much weight not
caving in on St. Ivan's spring? As engineers reinforced this
room in the early 1900s, they added a massive
granite support column. Granite is a highly
durable stone made up of 90% hard minerals. These properties allow
this one pillar to support the entire square up above. So while the city
above didn't actually compromise the
structural integrity of the subterranean room, it
did compromise the quality of St. Ivan's healing water. As Budapest continued to grow,
the polluted Danube river began to rise and mixed
with St. Ivan's spring. Over the years, the spring
became more and more contaminated. So in the early 1960s,
Budapest engineers had to find another source to
feed the great Gellert baths. They carved a mile long
tunnel into the Hillside and dug 13 holes along
it using the newest deep-drilling
technologies of the time. Approximately, 200
feet down every well hits upon a natural
aquifer beneath Gellert Hill. Since all 13 wells draw from
the same enormous aquifer, the spa only needs to
operate the two wells to feed the entire complex. But engineers found much
more than a new source of fresh water for their baths. While digging the
tunnel, they actually found a cave home believed
to have belonged to St. Ivan himself. What a dramatic, completely
dramatic difference from being in a constructed
tunnel to a national cave. Yeah. So St. Ivan, this is
probably his dwelling. This could have been a platform
where St. Ivan would have done his healing.
- Yes. Now, and what's
above our head? The Cave Church. The Cave Church
is right above us. ERIC GELLER (VOICEOVER): We
were standing in a natural cave thought to be the home of St.
Ivan over 1,000 years ago. And directly above us was
the famous Cave Church of St. Istvan, or
St. Stephen, the King responsible for bringing
Christianity to Hungary. St. Istvan's cave
church was first inhabited by an order
of Pauline monks in 1924, long after hermit
monk St. Ivan's time. But it appeared the
20th century monks may have been aware of their
legendary counterpart that once healed beneath the ground. Let's see what we
can find up here. ERIC GELLER (VOICEOVER):
St. Istvan's cave church was connected to the underground
healing world of St. Ivan. And I had found the proof. It was a narrow
carved-out tunnel. Built for a
smaller man than me, a smaller monk than me for sure. ERIC GELLER (VOICEOVER): But
a thick layer of concrete stopped me from
going any further. In 1951, the Hungarian secret
police broke into the chapel above and arrested the
entire Pauline order and sealed up any connections
to the subterranean world of springs down below. OK, well, it looked like,
from my estimation, that was probably the basement
of the Cave Church. And also by my
estimation, St. Ivan must've been a
smaller man than I, because it's a very
narrow passage. ERIC GELLER (VOICEOVER):
Proper studies have never been done on this
hidden cave room, but evidence of this
mysterious abode, of St. Ivan's
healing springs, just adds to the mystery of
this legendary monk. And for the thousands
of tourists and bathers using Gellert Bath
above each day, they have no idea of
the water world hidden beneath their feet, a world
where modern pumps harness ancient springs and continue to
bring them healing water used before them by the Romans,
the Turks, and maybe even a hermit monk named St. Ivan. Right now, I'm in one of
the many tunnels that make up Budapest's metro system. But building a metro or
anything else in this city isn't an easy task. Anytime you dig,
you're bound to run into a cave or a
thermal spring or maybe even an underground hospital. So the challenge for
engineers in Budapest is, how do you build a modern
city above without destroying its underworld? ERIC GELLER (VOICEOVER): Being
an archaeologist in Budapest is like being a treasure hunter. No matter where you
dig, you can literally unearth a priceless artifact. But you're always in
a race against time. Like in most major
cities, in Budapest there are new buildings being
built, metro lines being dug, and streets being
paved over every day. But with its endless cave system
and layers of buried history, archaeologists are challenged
with balancing modernization with conservation. Hello. It's nice to meet you. Nice to meet you as well. Karoly Magyar from the
Budapest History Museum. ERIC GELLER (VOICEOVER):
Karoly Magyar is a leading
archaeologist in Budapest. He's called to every
new construction site of historic significance to
determine if breaking ground will unearth Budapest's past. Karoly and his colleagues have
found two new sites in Budapest that have actually
rewritten ancient history. The first one was at
the construction site of a new hotel. Well, this is a modern
hotel as you can see. But in fact, we have got
medieval remains downstairs in the basement of this
brand new building. So this is the construction
area at the moment, of course. Sure. OK. Wait a minute,
wait a minute, OK. Look at what I'm finding right
now, just before my eyes. These look like bones
or they look like tools. No, they are animal
bones just beneath. You can see wooden structures. They are all from the Middle
Ages, from the 15th century. ERIC GELLER
(VOICEOVER): The hotel was being built directly
on top of Budapest's past and in the area that will one
day be its basement, Karoly and his colleagues found remains
of a massive and supposedly indestructible
15th century tower. But this was much more
than just a tower, it was a key to toppling the
kingdom that sat fortified up above. This was a strategical
point, as you know. It seems somewhere around the
middle of the 16th century, this part of the
place collapsed, most likely because it
was hit by artillery fire. We found some cannon balls
inside, stone cannon ball. You're kidding. This is about 20
centimeters in diameter. But over there, you can
see some much bigger ones. Oh, my goodness. Right, right, right. About 40 to 50
centimeters in diameter. You can see that if
you fired enough of these and certainly the larger ones,
eventually this structure caved in. ERIC GELLER (VOICEOVER): In the
16th century, the city of Buda was constantly under attack. The Ottomans had been
launching invasions into the city for a century. And this tower was a key target. It protected the south
end of the city walls at the banks of the
Danube, but it also had another function no one
knew about until recently. KAROLY MAGYAR (VOICEOVER):
It pumped up the water to the area of the palace. It's situated about 60
meters higher than this place at the foot of the hill. There must have been some
kind of pumping machinery that pushed up the water onto
the top of the hill. ERIC GELLER (VOICEOVER): This
tower protected a middle-age water pump, a key
source of water for the Hungarian King himself. Cut off this supply, and the
royal palace would practically go dry. Since it's a brand new discovery
and nothing like it has ever been found in Hungary before,
archaeologists are still unsure exactly how it worked. But they guess that the pump
looked something like a seesaw. The seesaw, or wooden board,
hovered above a ditch that was connected to a spring nearby. The wooden board stretched
as long as 20 feet and was fitted to
the wall at an axis. It's possible that at
each end of the board were containers that rotated
as the board moved up. The container scooped
up water from the ditch, raised it to the
top of its rotation and dumped the water
into another channel that carried the water to the
next pumping station. The water eventually reached
the castle 200 feet above. This is an active
dig right now. So if we were to stay down
there for a few minutes, we don't know what we'd find. He's found something
right there right now. Is that from a pot? It seems to be from the
16th or 17th century, so the late Turkish period
or early modern period. I say, if you keep digging,
you're bound to find more. We hope so. But there are serious
structural problems. And we have to work
here very carefully. ERIC GELLER (VOICEOVER):
In the less than two months since excavations began,
Karoly uncovered a clue to an unknown ancient technology
long since buried underground. If they continue to dig,
they could unlock the secrets to the medieval water pump. But they could also destabilize
the foundation of this brand new building. But that's not the only
site Karoly is working to save from the bulldozers. Just up the road on the main
square of Castle Hill Karoly's colleague Andras
Vegh is excavating the old Jewish
quarter of the city from the late 11th or
early 12th century. This spot, its
spectacular here. I mean, look at
the size of this. You can see here cellars,
cellars from the beginning of the town from
the Middle Ages, from later Turkish period,
and modern period and so on. That's a great mixture here. ERIC GELLER (VOICEOVER):
In the 13th century, the Mongols slaughtered half
the Hungarian population. But in the wake
of such disaster, Budapest boomed thanks
to King Bela IV. His strategic decision to move
the city to the hills of Buda protected it from further
attack and allowed the city to flourish. Settlers were invited
from across Europe to help rebuild the city. In the Western end
of Castle Hill, a Jewish quarter
was established. Now, look what you're
standing on here. Yeah. I just noticed this. What do we have here? Though I'm guessing because
we are in the Jewish quarter, we're not going to find
any pig bones, am I right? [laughs] ERIC GELLER
(VOICEOVER): Today there was a bulldozer on top of us. And in the next few years,
it could be a building. The land is owned by the state. And while there are no
immediate building plans, the fate of the site is unknown. But by law, if this site
is in an historical area, archaeologists must come in
and document what's here. In some cases, like the
hotel Karoly is excavating, the ruins remained
exposed and preserved. But in others, the site
is filled with sand to protect the ruins. Next, a layer of concrete
is poured over the sand. The concrete protects
the ruins but also acts as the sturdy foundation
of the new building that will one day sit on top. It can be heartbreaking
for urban archaeologists to bury a dig site. But in many cases, they
know breaking ground for new construction is often
the only way urban discoveries are ever made. OK, so should we go down? Right now, I'm already about
10 feet below street level. And looks like I'm going
down another 15, 20 feet. Oh, wow.
- This is [inaudible]. Yeah, this is it. This is a mikvah. And it still has water in it. ERIC GELLER (VOICEOVER):
Mikvah's are an ancient tradition in Judaism. Both men and women use them to
perform purification rituals. And I'm saying,
there's water in there. ERIC GELLER
(VOICEOVER): Each bath was dug beneath
street level and used a shaft in the center of the
room to let in pure rainwater. The rain would fill the bath
enough so that the participants would be completely
immersed in water. And this is a
new discovery here. Do you think there is many
more discoveries to be made in Budapest? ERIC GELLER (VOICEOVER):
Food, water, and shelter are three basic
requirements of life. And for centuries,
Budapest's underworld has provided its citizens
with both water and shelter. That's two out of three. There's no denying
that Budapest, more than any other
city in the world, owes its existence to
the city of caves below. And while today
the caves are more of the subterranean playground
for spelunkers and treasure hunters than a life
saver or a life giver, we can be sure that secrets
dating back to the dawn of time are still hiding
beneath the streets. Today, even the experts don't
know everything about the world beneath these streets. But years from now, who
knows what they might find-- a passage to an undiscovered
cave, a secret escape tunnel, or a lost treasure of
medieval artifacts. Or maybe they'll dig
beneath these streets and find the remains of today.
