- Question, what's the
highest mountain on earth? Did you like just about
everyone who's watching say, Mount Everest. Oh, give yourself a point.
Now let's ask the opposite. What's the deepest hole on earth? Some smart Alex among you might be saying, the Mariana Trench, but that's wrong. There exists a hole so deep
it exceeds the deepest depth of the famous Mariana Trench, and shockingly, it was dug out by humans. However, what they found at
the bottom, no one expected. What did they find? How deep did it go? And how deep have we dug before? Come with me as we take a terrifying look at some of the deepest holes on earth and what lies at the bottom of them. (upbeat music) Chand Baori, when you think
about what the deepest holes on earth look like from the surface, I bet you imagine a jagged
circular hollow cutting into the crust and leading down into impenetrable darkness and doom. But that's not always the case. Take Chand Baori, for example, found in Rajistan Eastern India. This isn't a simple circular
cavity cutting into the earth, but a complex stepwell. If you didn't know, step wells are wells with a long corridor of descending steps that drop down to the water level. This particular step well
built during the eighth century provides the areas around Rajasthan with a dependable water source. Centuries before modern
water delivery systems were introduced. As it happens, Chand Baori
is the deepest step well in the whole world. In all its striking structure
consists of 3,500 narrow steps cascading 13 stories,
constructed 100 feet down under. That depths, the equivalent
of around five giraffes stacked on top of one another. And what's the reward for
braving the colossal climb down? Murky green, stagnant water, delicious. Still, it's worth it for the view alone, which isn't something you can
often say about, a big hole. (logo whooshing) Yamal hole. Not all deep holes are
the result of manmade construction, however. Helicopter pilots flying
over the Yamal Peninsula and the Siberian wilderness were greeted by this unnerving site back in 2014. Is that making anyone else's skin crawl? This perfectly circular hole
stretches 66 feet across and has a terrifying 170 foot drop. The question is, why did
a giant hole open up here? Conspiracy theorists pointed
to everything from media rights to stray missiles and even aliens. Yet scientists seem to
think this curious cavity may have been formed by
a pingo, no, not him. A pingo forms when a layer
of frozen ground is pushed up by water that's managed
to flow underneath it. As the water freezes, it
expands to create a mound. Warming temperatures causes
the mound to melt and collapse, leaving behind this
massive unnerving crater. Another theory is that
as the ground warms up, underground ice formations may thaw. This could release long held methane gases that force their way to the surface before exploding out, causing
giant graters like this. Well, whatever the cause
of this gigantic hole, extra terrestrial or otherwise,
one thing's for sure, you wouldn't wanna fall down it. (logo whooshing) Monticello Dam spillway. Now, it's not just our land
that's filled with massive and mysterious gaps. These holes can also be
found in the world's waters like this one, that first
glance you may think that this is a massive magical
vortex that'll transport you into some marine dimension, but sadly, it's not quite as glamorous as that. This water waterhole
is actually a spillway. Spillways are basically overflow drains, ensuring that when reservoir
water reaches a certain point, excess water flows into the spillway instead of over the dam, which could cause damage to the
structure of the dam itself. When Monticello Dam in
California reaches capacity, its circular spillway
channels water down at a rate of 48,800 cubic feet per second. That's more than half the water that makes up an Olympic
sized swimming pool. As for the spillway itself,
it has a daunting depth of 200 feet. So it's about as deep as an
18 story building is tall. Even if I had wings, I wouldn't
want to go near the Oh, I'm sure he is fine. Unfortunately, the
temptation to take a dip here wasn't just too great for the
bird, but also for a woman called Emily Schwa. In 1997, she decided to
swim near the spillway before getting caught up in the
powerful current it created. Somehow she managed to hold onto the rim for about 20 minutes, but
she was eventually sucked in and sadly didn't survive. So not only are these
holes unnerving to look at, but they're also literal
man and bird eaters. (logo whooshing) Devil's sinkhole. In the wilderness of
Texas, 1400 miles southeast of that sinister spillway, you'll find another unnerving hole, except this one is much drier. Explorer Ammon Billings first
discovered this sinkhole back in 1867. He was so scared of
what he saw before him. He referred to it as The
Devil's Own Sinkhole, and in fairness, it's a
pretty apt name for the hole. The main cavern is a circular
65 foot wide crevasse and drops down a hair
raising 350 feet deep. That means you could fit the
Statue of Liberty in here base and all and still
have 40 feet to spare. If that wasn't devilish enough,
the sinkhole is also home to 3 million Mexican free tailed bats that nest in the caverns walls. (soft music) While the devil himself would
be proud of this sinkhole, he didn't make it. It's actually the result
of a natural process which started around 1 million years ago when slow moving acidic
groundwater carved a huge cavity into the limestone here as
the water table dropped, the water that once held up
the ceiling of the cavern drained away, leaving the roof to cave in, creating this incredible formation. And while it may not be the
work of the devil's hands, and this sinkhole is definitely hellish. (logo whooshing) Well of Hell. Speaking of hellish holes,
that brings us to our next creepy cavity, found in the
desert landscape of Al Mahara in Eastern Yemen. Here the land stretches for miles until you reach this strange circle that looks like it's been
cut into the landscape known as the Well of Hell. This vast void is close to 100 feet wide and a jaw dropping 367 feet deep. If that doesn't have you
scrambling backwards, those brave enough to get
near the hole, report a foul, almost unbearable stench
wafting up from below. It's so pungent it's led locals to suggest that the Well of Hell was
created as a prison for demons. Despite those creepy claims,
a team of 10 daring explorers journey down the hole
to discover what exactly was lying at the bottom of it. They didn't find any demons, but they did come across
waterfalls, stalagmites, cave pearls, snakes and birds. Not the alive kind, though maybe
that's what was responsible for the awful aroma. One thing is for sure though
this hole wasn't formed with the purpose of housing evil spirits. Nope, it's just an ordinary sinkhole. Okay, so it's not a demon prison, but considering it's home to foul smells, dead birds and scary snakes,
I'm still not too keen on dropping down this humongous hole. (logo whooshing) Great Blue Hole. As we've seen with the
Monticello Dam spillway, huge holes can perforate
water as well as the land. But while that soaring
spillway is found in a dam, some others create vast voids
in the middle of the sea. Take for example, the aptly
named Great Blue Hole. This bit found 40 miles
off the coast of Belize formed around 15,000 years ago. This sea shaft was once
a limestone cave system found on dry land when
sea levels were lower. Over time, acidic rain
reacted with the limestone causing it to dissolve and
the cave roof to collapse. Then when sea levels rose
again, the cave system began to flood creating what
is now the great blue hole. In total. The great blue
hole is a staggering 1043 feet across and drops
down a gut wrenching 407 feet, which is far deeper than
the surrounding water. As a result, it holds a much darker color than the surrounding water
making it pop mount from the sea. But it's not just the dizzying depths that you've gotta watch out
for, considering that this place used to be a cave, the sinkhole is filled with stalactites and stalagmites. It's also home to a range of marine life, from Caribbean reef sharks to eagle rays and even ferocious barracuda. Safe to say it's not a place
you wanna find yourself at the bottom of for a number of reasons. (logo whooshing) The Big Hole, if you
thought a 400 foot drop was a long way down, you've
not seen anything yet. Located in Kimberly, South Africa. This is the Kimberly Diamond Mine, even more appropriately
named The Big Hole. This chasm is enormous, so
enormous that it stretches over 1500 feet wide and
plummets down 705 feet deep below the water line. The question is, what's
such a huge sunken hole doing in the middle of the
South African countryside? Well, turns out way back in
1871, diamonds were found on the site sparking a
diamond rush to the area. Just one year into the diamond discovery, the population of diggers grew to 50,000. Unfortunately, as the digging progressed, many men met their end
in mining accidents. While the unsanitary conditions
lack of food and water and intense summer heat also wiped out much of the digging population. By 1914, after untold losses of workers, excavation on the mine ceased, but it wasn't all doom and gloom. By that point, over 22
million tons of rock had been excavated, yielding
31 tons of diamonds. For context, that's the weight
of four African elephants. Jeez, no wonder that hole is so huge. After it was abandoned and the large pumps keeping all the groundwater
at bay were turned off. It was left to collect
ground and rainwater and began accumulating
what is now 130 feet of picturesque looking turquoise water. However, those 100 foot tall sheer sides are near impossible to scale. So pretty as it is. I wouldn't
recommend jumping in there. Well, not if you ever wanna make it out. (logo whooshing) Dragon Hole, although the big hole trumps the great blue hole for depth, there's one marine cavern that plunges even further down than the
South African diamond mine. This is the dragon hole
found in the South China Sea. It's the world's deepest blue hole totaling out at a
staggeringly deep 987 feet. That makes it exactly as deep as China's Wang Kong Tower is tall. Like the great blue hole this
would've formed as a result of water eroding the limestone causing the cave roof to collapse. Then as sea levels rose,
the blue hole emerged. According to local legend, The Dragon hole is where the monkey king
from the famous Chinese novel "Journey to the West" acquired
his famous golden cudgel from an undersea kingdom
ruled by a dragon. Sadly, it doesn't look
like this big blue hole is actually ruled by a dragon deity. Although this place does
hold some marine mysteries, the upper portion of
the dragon hole is home to at least 20 species of fish
yet below depths of 300 feet. Virtually nothing exists. It's because the dragon hole
doesn't have any open caves that lead in the ocean tides,
and this results in isolated and stagnant deep waters
that are devoid of any oxygen and no oxygen equals no life. The dragon hole, scary by name
and even scarier by nature. (logo whooshing) WoodingDean Well. Placed in a sidewalk in the
middle of Brighton, England. You'll find this inconspicuous
little structure, but modest as it looks at first glance, this is actually the site of
the WoodingDean Water well. The deepest hand dug well in the world. In total, this whopping well goes down. Seriously get ready for this, 1,285 feet, meaning it's a deeper than
the Empire State Building is tall, excluding its antenna. So what exactly is such a huge hole doing in the middle of a sidewalk? Well work started on
this shaft back in 1858. Back then, it was dug to provide water for a nearby workhouse in
exchange for food and a bed the workhouse residents were
expected to dig the well. It was a task that was
carried out night and day for four years with only
candlelight to dig by. Can you imagine climbing up and down an Empire State building
sized well every single day with just a flicker of light to show you where you were going? Eventually, after four grueling years, the workers finally struck water. Finally, all that hard
work was worth it, right? No, despite the massive cost,
enormous effort and promise that the well would
save the town of fortune and water rates, wooding
Dean well was only used for four years before
being abandoned in favor of a more practical water supply. Okay, if I'd been one of those workers that would've taken everything in me not to throw myself down
the well after that. (logo whooshing) Mir Mine. Well, you might not have
assumed that WoodingDean Well was a deep drop at first glance, the same can't be said for Mir Mine. This open pit diamond mine in Siberia has a diameter that
stretches 3,900 feet across, and when it comes to depth
mere mine plummets down a massive 1,722 feet. As the name suggests, this
site was once an open pit mine after Soviet geologists discovered diamond bearing deposits in the area. In 1957, mining began,
but this was no easy task. Being located in Siberia where
average winter temperatures dropped to minus 70 degrees Fahrenheit, the ground was covered
in a rigid permafrost. To break through this,
workers had to use jet engines to thaw the ground. Despite the difficulties
digging Mir Mine quickly became the largest diamond
mine in the Soviet Union, producing over two tons
of Kimberlite diamond per year in the 1960s. Mining operations continued until 2017 when flooding rendered the
mine too dangerous to use. But this place isn't just a hazard to those working within it. It's also a threat to
aircraft flying overhead. It sounds crazy, but apparently
the earth warms the air inside the depths of the hole compared to the freezing
surface temperature. The warm air inside the hole
rises while the cool air around it sinks such a
big temperature difference between the in hole air
and the above ground air results in a deadly vortex
capable of dragging down aircraft into the chasm. While there have been no recorded accounts of this actually happening, man alive, I'm gonna have nightmares
about this huge hole. (logo whooshing) Berkeley Pit, almost 5,000
miles away from Mir Mine is an even more profound pit. Located in Butte, Montana,
you'll find Berkeley Pit a formerly open pit copper mine. The pit operated from 1955 to 1982. In that time, around 1 billion
tons of copper, silver, and gold were extracted from the site. Considering the amount
of material extracted from this place, it's no surprise there's pretty huge hole here. In all Berkeley Pit
stretches a whole mile across and is half a mile wide while it drops down a staggering 1,780 feet, meaning the one World Trade
Center could fit in here. In fact, this hole is
so mind blowingly big it can even be seen from orbit in space. Due to the pit being so deep, the groundwater has now
infiltrated the empty hole, filling it with 900 feet of water. But this isn't just any old water. Due to the presence of sulfuric acid that's leached from exposed rocks, the water has an acidity of 2.5 pH. For reference, that's about
as acidic as lemon juice. But not only is it acidic, it also has a high
concentration of metals. It contains over 70,000
copper parts per billion over 50 times higher than the
human drinking water standard. In fact, this water is
so toxic that in 1995, a flock of migrating geese died after they landed in Berkeley Pits Waters. Lab tests shows the insides of the birds were lined with burns
and sores from exposure to high concentrations of
copper, cadmium, and arsenic. Yikes, efforts have since
been made to purify the water and make it safe for wildlife. But still, canonically
Montana was once home to the biggest toxic pit
in the world, which seems, let's be fair on brand.
(logo whooshing) Xiaozhai Tiankeng. Anyone trekking through the
beautiful mountainous landscape of Chongqing, in southwestern
China, can expect to see miles of lush rolling green hills. Well, for the most part. You see in the middle
of this emerald abyss lies this colossal circular cavity. From above, this might
look like some enormous alien footprint, but this
is in fact, oh here we go. Xiaozhai Tiankeng the
world's deepest sinkhole and the most difficult thing to pronounce if you're not a native, at least I tried. This huge hole formed gradually
due to the flow of water carving out underground cave systems. Over time, the underground
cavities became larger and larger until the cave
roof collapsed in on itself resulting in this sinkhole. And as sinkhole go,
Xiaozhai Tiankeng is huge. For starters, it measures 2054 feet long and 1,762 feet wide. On top of that, this place
drops down 2,172 feet deep. That's over twice as deep as
the UK's tallest skyscraper The shard is tall In all, some 1,285 flora and
fauna species found here, including the rare ginkgo
plant, elusive clouded leopard, and the six foot long
Chinese giant salamander. Safe to say this humongous
hole is giving me a sinking feeling.
(logo whooshing) Bingham Canyon Mine. Much of the landscape in
the rural region southwest of Utah's Salt Lake City,
are dominated by tall mountainous peaks much, but not all. You see, this is also home
of the Bingham Canyon Mine, the deepest open pit mine in the world. The mine has been in
production since 1906. Since then, it's produced some
19 million tons of copper, more than any other mine in history. Even today, the mine is still
in use, employing 2000 workers and excavating some 450,000 tons of material every single day. As you can imagine, so much excavation has made Bingham Canyon Mine humongous. In all. It stretches two
and a half miles wide and a colossal 3,960 feet deep. That's over eight times the height of the great pyramid of Giza. And considering that
excavations here will continue until 2032, it won't
be long until this pit gets even wider and deeper, holy moly. (logo whooshing) Veryovkina Cave. While you can see Bingham Canyon Mine from way up in the sky,
the same isn't true of an even deeper hole. Hidden in the lush mountainous landscape of Abkhazia , Georgia,
you might not even notice this tiny 10 by 13 foot opening. But this small shaft is
actually the entrance to Veryovkina Cave, the deepest
known cavern in the world. And the cave was initially
discovered in 1968 by Spelunkers who reached
a depth of 377 feet. But that's just the tip
of this cavernous iceberg. Explorations have continued ever since. With spelunkers finding new
untold depths to this place. in 2023, a team of
explorers descended down a staggering 7,293 feet. That means this place
is almost twice as deep as the gigantic Bingham Canyon Mine. So large as the descent down
that it takes spelunkers a grueling four days of scaling
walls and squeezing through crushingly tight spaces
until they reach the bottom. Sounds impressive, but can
you imagine how grueling it'd be to spend eight days
trekking up and down this place. True to its name, this
cave is a very deep chasm. (logo whooshing) IceCube Neutrino Observatory,
in a region even more remote than the desolate Abkhazian mountains, you'll find the IceCube
Neutrino Observatory, And no, before you ask,
scientists aren't monitoring some supersized ice cube. Instead, this observatory found at the Amundsen-Scott South
Pole Station in Antarctica is designed to study neutrinos. Neutrinos are tiny massless
charge list particles that rarely interact with any particles, making them almost impossible to detect. Although occasionally neutrinos do react with water molecules in ice. And this is where the IceCube
Neutrino Observatory comes in. Using a hot water drill,
86 holes varying at depth between 4,750 and 8,000 feet
were carved into the ice. For reference, the deepest of those holes is almost six times the
height of the Willis Tower. A vertical string was placed in each hole with each string holding 60 light sensors. These light sensors were then
used to detect any blue light the neutrinos emit,
allowing scientists to infer the presence and properties of neutrinos. In 2013, just three
years into the project, the ice cube detected 37
neutrinos that originated from outside of our solar system. Man, who knew we could
detect these alien atoms and to think all it took was
drilling 86 humongous holes in the Antarctic ice sheet.
(logo whooshing) Mel's Hole. But the world's deepest
holes aren't always found in desolate places or so it seemed. Back in February, 1997, a
man who identified himself as Mel Waters, called up Coast
to Coast AM radio station. Waters claimed that he owned a property near Ellensburg, Washington, that contained a mysterious hole. According to Waters, the
hole had an unknown depth. He claimed after using
80,000 feet of fishing line that was attached to a weight, he still hadn't hit the bottom. That meant that the Burge Khalifa, the world's tallest building
could fit inside this chasm 30 times over, wowza. But depth isn't the only
crazy thing about Mel's Hole. Waters also claimed that
the chasm had magic powers. Apparently, a neighbor's dead
dog had been discovered alive sometime after it was
thrown into the hole. Water said that due to the
hole supposed magic properties, us federal agents seized his land and funded his relocation to Australia. But bonkers as that sounds
online conspiracy theorists pointed out that the hole is
near to Yakima Training Center, a US army training base. Who knows, maybe the hole is home to some secret government alien activity. In reality, though, geologists
say such a huge hole can't exist, something
that deep would collapse into itself due to the tremendous pressure and heat from the surrounding strata. Fair to say, there are a
few holes in Mel's story. (logo whooshing) Kola Superdeep Borehole. While Mel's hole seems
pretty baseless, literally, what's the real deepest hole in the world? Well, the answer lies
in the Kola peninsula, a remote region of northwestern Russia. This is the site of the
Kola super deep bore hole, the world's deepest recorded hole. Although you wouldn't guess it judging from what it looks like from the surface. Yeah, that's right. The
deepest hole in the world is underneath that rusty
abandoned metal cap. So how deep is it and
what's underneath the cap? To find out, we gotta
go back to the 1960s. During this time, the
Cold War beneath the US and the Soviet Union was at its height with each trying to outdo one another. While history remembers the space race, both also engaged in a race
to the center of the earth, America's project Mohole
drilled to 600 feet into the Pacific Ocean. But the Soviet scientists blew that effort out of the water with the
Kola Superdeep Borehole. Drilling began in 1970 with the
help of the Uralmash-4E Rig. When the operation ended in
1989, the nine inch wide hole had reached a mind-boggling
depth of 40,230 feet or 7.619 miles. For context, that's over five miles deeper than the world's deepest
mine, and nearly a mile deeper than the bottom of the Mariana Trench. If that wasn't crazy enough,
the hole's depth is the height of Mount Everest and
Mount Fuji placed on top of one another. So deep is this hole that if
you somehow manage to fall down this thing, it'd take
a terrifying 50 seconds before you crash to the bottom. So how did they dig so deep? Well, when drilling
began, it was easy to plow through the granite rock. But around four miles down,
the layers became more dense and difficult to bore into. As a result, drill bits
broke, causing the diggers to change the drilling
direction several times. Gradually they made it further down, but as they got over one obstacle, another soon popped up, the heat. Due to the heat flow
from the earth's mantle. The further down you
go, the hotter it gets. At over seven miles down temperatures hit 356 degrees Fahrenheit,
twice what was expected at that depth, the soaring heat
was beyond the capabilities of their drilling equipment,
leaving Soviet scientists to abandon the project in 1992. And that was that, or was it? Some online theories
have suggested something far more eerie led to the
end of the experiment. It said that wicked wailing
screams of tortured souls were recorded from the
whole leading to the belief that it went all the way
down to the underworld. But before you chew off the
last of your fingernails, it's likely that this awful
audio is just an urban myth. For starters, the recording
devices wouldn't be able to withstand the 356 degree
Fahrenheit temperatures. And while a myth busting
website analyze the sounds and found that they were
suspiciously similar to audio used from the 1972 horror
movie, "Baron Blood," even still a potential
portal to the underworld that burrows down close to
eight miles below the earth surface is certainly a hair raiser more, should I say hell raiser.
(upbeat music) Then with that, we've delved to the bottom of the world's deepest holes. Have you stumbled across
any huge holes of your own? Let me know down in the comments below, and thanks for watching.
(upbeat music)
