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Deep Cave Discoveries That Left Scientists Baffled


| LAST UPDATE 06/29/2021

By Scarlett Adler

Caves are home to some of the world’s strangest discoveries. Whether it’s glowing bacteria or unknown species, scientists are often puzzled by what they find in their depths. Here are some of their most surprising findings…

Proof of Life?

Much to their surprise, scientists stumbled across a remarkable revelation while studying an ancient cave in Naica, Mexico: Living organisms - believed to date back as far as about 50,000 years.

Largest Crystals cave wondersLargest Crystals cave wonders
Wikimedia Commons via Assignment Houston One

From the looks of it, the cluster of micro-organisms had been thriving underground. They were living on rich minerals found inside crystals within the cave. These findings changed what scientists had previously understood about life on this planet. And this wasn’t the only strange discovery found in caves over the years...

Graveyard Of Lemurs

While deep-diving in underwater caves off the coast of Madagascar, a group of divers discovered a number of bones. They were the bones of an extinct ancestor of the animal we now know as the Lemur. These animals were thought to be extinct for at least 2,000 years. So why were they there?

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AP via Shutterstock

A new theory about the cave lemurs soon emerged. Apparently, these giant animals had been moved by the current until they eventually ended up in the underwater cave. Their peculiarly large skeletons were amazing, but not uncommon. Many extinct species were also exceptionally large, with some spanning as high as 10 feet!

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West Wycombe Hauntings

In West Wycombe, South Central England, a group of caves has been met with an unusual reputation. For years they have been given the nickname Hellfire Caves. Why? They are believed by many locals to be haunted. This is largely due to a number of strange carvings that can be found within.

Cave Mysteries Ancient SecretsCave Mysteries Ancient Secrets
Mike Kemp via Getty Images

These wall carvings are believed to be connected to the Devil, hence the title ‘Hellfire Caves.’ Though there’s no biological mystery here, the mysterious drawings are enough to attract people from all over the world. Though, many spooked visitors dare to venture inside.

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The Walls In Tabasco's Cave

The substance that grows in a special cave in Tabasco, Mexico, has truly earned its nickname. It’s known as Snottite, which is particularly fitting given the specimen is sticky and viscous. Currently coating most of the walls of the cave, it is so sticky that it tends to catch passing insects too.

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Wikimedia Commons via Mnolf

It’s also a particularly hearty substance. The cave it resides in is near-uninhabitable for any other living organism, but in this habitat, the Snottite thrives. The phenomenon is referred to as extremophilic, a word that refers to organisms that can flourish despite the inhospitable environments it lives in.

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Cramped Conditions

Perhaps another case of extremophilia lies in the caves of the Monfort Bat Sanctuary. These caves are unlivable for most, with the exception of tiny bats. These creatures use their echolocation to navigate the massive caves, meaning they use sound to guide them through their environment.

Monfort Bats Guinness RecordMonfort Bats Guinness Record
ImageBROKER via Shutterstock

This cave on Samal Island, located in the Philippines, is currently home to a whopping 2.3 million of these tiny flyers! And conservation experts report that it is the biggest group of fruit bats anywhere on Earth. The Monfort Bat Sanctuary was listed in the 2010 Guinness World Records as an important landmark for bat-lovers.

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Smoo Cave Cemetery

Here is another set of caves with a strange history, located in Northern Scotland. Most archaeologists have seen their fair share of unearthed bones, but the horrible artifacts found in the depths of Smoo Caves tell a story that most doesn’t come across often.

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Wikimedia Commons via Florian Fuchs

Within this cavernous hideaway, a range of gruesome remains was discovered, including decapitated skulls, spears, and body parts left in troughs. Thanks to the rather extensive collection inside, scientists indicated one specific cause. The cave must have once been the site of human sacrifices.

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Catskill Mountain Statue

But violent remnants certainly aren’t the only spooky discovery on this list, as this cave in New York State has proven. Back in 2016, a group of hikers was exploring a cave in the Catskills Mountains, when they came across a bizarre statue placed inside.

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Eric Lafforgue/Art in All of Us via Getty Images

It has since become known as the Crone, a hand-carved figure with six nails driven into its eyes. The Crone has gained a lot of attention since its discovery, possibly due to the supernatural atmosphere the hikers felt upon discovering it. Many people have wondered how the statue came to be in the cave, and why.

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Century-Old Salamanders

But horror and the aura of the supernatural world isn’t the only thing that can be found in caves around the world. Many of these caverns can summon a feeling of awe at the natural beauty found within. Here we have the Olm salamander, a recently discovered species that amazed the scientific community.

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Jan-Peter Kasper/EPA via Shutterstock

This unusual amphibian can be found in Slovenia and Croatia. They can stay alive for as long as 100 years, and retain the same set of girls throughout their lives, a unique feature amongst amphibian species. Because they are completely blind, Olm salamanders use electro-sensation to navigate their surroundings.

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Movile Cave: 1 of 3

Romania is a country rife with frightening and even supernatural folklore. But in the seaside city of Constanta, there is a horrible phenomenon that isn’t paranormal in the slightest. A deadly cavern called Movile Cave near the city has been releasing hydrogen sulfide for over 5 million years.

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It’s no wonder humans no longer set foot in these grottos, though other species have chosen to brave the inhumane conditions. Some species of centipede and arachnid have chosen to call Movile cave home, unaffected by the toxic gas and sulfuric stench.

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Movile Cave: 2 of 3

But how did one place come to be so toxic and threatening to human life? Many scientists have excavated the depths of the cave (with adequate protection, of course) to answer this question. And one thing they found? The Movile cave contains only half the amount of oxygen that humans require for survival.

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Barcroft/Contributor via Getty Images

Without appropriate equipment, anyone who ventures into this cave can easily experience hypoxia and perish without sufficient oxygen. But scientists are able to use various diving tanks and gear that allow them to navigate the depths of the cave for short periods at a time.

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Movile Cave: 3 of 3

But if the environment was so extreme, why did these scientists keep returning? The truth is that the toxicity of the caverns was not the most fascinating discovery of their deep dive. Instead, it was the realization that the waters in this poisonous habitat shared many conditions with ecosystems above ground.

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Wikimedia Commons via Michel Vuijlsteke

To be specific, there is very little sunlight that reaches into the caverns. But the bacteria within still get sufficient levels of carbon dioxide - just like sea-level vegetation. Amazingly, this is the only known case where such a circumstance has ever occurred on our planet.

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Cave Art

Over hundreds of years, the interior of endless caves around the world has been protected from harsh climates, weather conditions, and human destruction. As such, they have preserved many cultural artifacts over time, much to the delight of the scientific community.

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And there have been many sightings of this around the world, including these paintings left behind in a cave in Argentina. Markings on these cavern walls have been traced as far back as 13,000 years! Studies have proven that the fascinating drawings were made from chalk powder.

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Neanderthal Society

Neanderthals were much more than just proto-humans - as shown by these ancient formations found in a cavern in France. The structures found here are thought to be symbols used for spiritual rituals, sharing a glimpse into the complex world of Neanderthals that have rarely been depicted before.

Ancient Neanderthal Religion WorshipAncient Neanderthal Religion Worship
Wikimedia Commons via Luc-Henri Fage/SSAC

In this cave, the Neanderthals used nearby mineral deposits for their ritual ceremonies, showing the magnificent scope of the tradition. Heaps and circles were dotted throughout the cave system. And while they don’t look like much to us, they gave scientists great insight into the history of Neanderthals.

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Mighty Anaconda

Any Ophidiophobes reading this may want to turn away. Deep in the Brazilian caves of Altamira is a slithering snake that has broken the record for the largest snake observed in human history. This special title formerly belonged to ‘Medusa’ of Kansas City, but at 880 pounds and 33 feet, this serpent takes the cake!

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Franco Banfi/Solent News via Shutterstock

This beast was found by a group of Brazilian construction workers and was first seen disappearing even deeper into the cavern. Using a construction crane, local officials were finally able to pick up the giant Anaconda. Since then, exploration has been done to gauge whether any of its serpentine kin lurk below.

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Treasures Of History

Here we have another stunning discovery that has furthered our knowledge of Neanderthals. As it turns out, building caves and painting cavern walls weren’t the only things the species achieved. Neanderthal jewelry has since been found in Europe, to the surprise of the scientific community.

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Geography Photos/Contributor via Getty Images

This ornamental discovery was made in Los Aviones, a cave located in Spain. Here, both drawings and jewelry were found scattered throughout the site. The jewelry is believed to be as old as 115,000 years and is adorned with marine exoskeletons. The paintings, in comparison, are only about 64,000 years old.

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The Lost People Of The Caves

There are endless other clues that tell us about past species that once walked the earth. Let’s turn to the island of Flores in Indonesia, where signs have indicated that a “lost” people once existed. Researchers have found a series of fossils in the Liang Bua cave with this fascinating evidence.

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Wikimedia Commons via Rosino

Though they bear the official name Homo Floresiensis, scientists have appropriately nicknamed the species “hobbits.” At only 3 feet tall, these small-brained humanoids apparently flourished on the island, despite often being the prey of Komodo dragons!

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Gruesome Cannibalism

Countless bones and skeletons have been found at the bottom of the world's caves, but this particular discovery is a little more gruesome than most. After another Spanish cave had been excavated, the skeletons of a Neanderthal family revealed a very disturbing tale.

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Wikimedia Commons via Nigel Davies

Tests that have been done on the bones clearly indicate that the family met a grisly end. They were almost definitely cannibalized by fellow Neanderthals, proving that the practice dates as far back as about 49,000 years. And if the tests are correct, the remains were most likely cooked in the process.

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Into The Earth's Core

Ellison’s Cave tells a story that most cave-divers and explorers would love to experience. The pit located in Georgia is as much as 12 miles deep, and the first recorded group to explore it descended down an incredible 586-foot drop. So deep, they may have thought they’d reached the center of the earth.

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Wikimedia Commons via Doronenko

Naturally, this pit doesn’t actually span that deep. But it goes down far enough that Ellison’s Cave has been placed at number 12 on the list of the deepest caves in North America. You can check it out for yourself, as the cave is open for cave divers to explore. But beware - it’s not recommended for beginners!

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Nature's Christmas Lights

Bacteria isn’t the most intriguing topic for most people, but in a particular cave in New Zealand, they are a cause for wonder and celebration! In the Waitomo Caves, the walls and ceilings are dotted with phosphorescent worms - or “glow worms”, as they are affectionately called by locals.

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Moritz Wolf/imageBROKER via Shutterstock

And these little bacterias put on a delightful show every night, becoming a popular tourist destination in the country. These worms light up inside the cave, creating a magnificent sight for any visitors passing through. You can even join a kayaking tour that floats you through the caverns!

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Puzzling Remains

By now, it should be no surprise that several cave discoveries have left scientists shocked and confused. For example, in a cave in South Africa, extensive evidence has been found for a hominin (pre-human) species. Amazingly enough, this species was completely unknown up until now.

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As ancient discoveries like this often do, the finding brought up many questions and not a lot of answers. Though the species has been given the name Homo Naledi, little else is actually known about the forgotten remains. However, it is believed that they walked the Earth roughly 3 million years ago.

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A Versatile Cave

Most ancient caves are left for centuries before being excavated by science. But this uniquely gorgeous cave has both an ancient and modern story behind it. The Reed Flute Cave, Or Karst Cave, has existed for millions of years, and it’s been put to good use during its time.

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DEA/C.DANI/I.JESKE via Getty Images

Interestingly, the Karst Cave was once used for shelter during World War II, becoming a safe haven for Chinese soldiers. These men sought refuge in the cave while they were under siege. Since then, many people have flocked to visit the site, both to pay homage to the soldiers and witness its geographical beauty.

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Cave Pearls

If we have learned anything so far, it’s that caves seem to be the perfect place for unique flora and fauna to thrive in. Whether it’s phosphorescent worms, blind amphibians, or giant crystal formations, many of the most unusual sights on Earth can be found inside. This brings us to our next fascinating discovery.

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Picture Alliance/Contributor via Getty Images

Known as ‘cave pearls’ by scientists, these aesthetically pleasing growths bear a surprising resemblance to their underwater counterparts. And they’ve certainly been a valuable find to the scientists who study them intently. We now know that these pretty stones are produced from mineral calcite, found within cavern waters.

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Blue Holes

Believe it or not, not all caves are found on rocky terrain in the hills and mountains. Many caves around the world are actually found underwater. And in the Bahamas, there is the highest density of caves in one area than any other place on earth - with over 200 ocean caves in its territory.

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Wikimedia Commons via U.S. Geological Survey (USGS)

It’s easy to see why these grottos have become known as ‘Blue Holes.’ These gaping underwater maws are easy enough to see from above, as they are characterized by a navy blue color that stands in sharp contrast to the ocean blue water around them. And though most underwater caves stand untouched, this is not true for all.

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A Secret Lake

Now that we know that caves can form on both terrain and water, it’s time to learn about the caves that do both! Nestled near a small island in Greece, is a fascinating phenomenon involving Melissani Cave, an on-land grotto with a large lake inside of it.

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Athanasios Gioumpasis via Getty Images

This remarkable landmark can be traveled to from the islands nearby, so it is frequently visited by tourists who flock to see the stunning site. The cave opens up to the sky above, letting in beams of natural light that often give the appearance of glowing blue cave walls.

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Strange Formations

Minerals are one of the more unique aspects of caves, creating all manner of unusual formations. Here we have the stalactite, a formation that spans down from cave ceilings. These stalactites are formed by a mix of water and minerals that drip downward, eventually combining and hardening into these shapes.

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Mike Kemp via Getty Images

The stalagmite is closely related to the stalactite. And while they are technically the same formation, they are created in reverse. Whereas stalactites form from the top of the ceiling, stalagmites form from the same mineral water. However, they rise directly up from the cavern floor.

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Hidden Secrets of Judea

In the hills of Judea lay an ancient secret. And when this secret was first unveiled, it caused shockwaves within the scientific community. It also challenged several aspects of history. Why? Deep inside these desert caves lay the Dead Sea Scrolls, one of the most valuable discoveries in recent years.

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DEA/ARCHIVIO J. LANGE via Getty Images

The Dead Sea Scrolls contained ancient religious manuscripts, artifacts with cultural and historical significance that could not be overstated. Along with these scrolls, a child's skeleton was also excavated. A basket was also found, the oldest discovery of its kind at about 10,500 years old.

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3 Weeks Underground

Many caves can be dangerous, despite how many people love to go cave diving and exploring. In fact, some are so treacherous that they simply cannot be explored. These are the caverns that are usually part of a complex caving system that burrows deep underground. Still, daring people have tried to go as deep down as they can.

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Hussein Malla/AP via Shutterstock

One great example of this lies in the Republic of Georgia, where a site known as the Krubera Cave offers one of the most challenging cave expeditions in the world. The furthest any group has ever gone is 6,824 feet down, leaving these cave-divers stuck underground for 3 weeks.

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Sensory Perception

If there’s one thing that caves offer to science, it is the knowledge of how a species can survive in extreme environments. Bats and the Olms Salamander are perfect examples, using echolocation and electro-sensation respectively to find their way around. And these species are not the only ones.

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Ullstein Bild via Getty Images

Have we mentioned the rare fish species that live their lives in cave pools? These fish have evolved to the point that they do not use their eyes anymore, as it is easier for them to navigate in the darkness through the vibrations moving through water. This is known as the lateral line, which hits the fish's vertebrae.

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The Cave of Crystals

As we know already, several cave crystals housed species that once existed as long as 50 million years ago. But there are other crystals that are fascinating in their own way. Here we have crystals that are so long, they rival some of the telephone poles we see every day!

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Wikimedia Commons via Alexander Van Driessche

These stunning formations can be found in the Cave of Crystals in Mexico and can grow as long as 36 feet - weighing as much as 55 tons! However, exploring this unique site is not for the faint-hearted. The inside of the cave can reach temperatures as high as 118 degrees Fahrenheit, proving fatal for some.

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More Questions Left To Answer

It should be obvious by now that caves are some of the most mysterious structures on earth, providing endless discoveries for mankind. Whether these are natural formations, human creations, or even just human remains, it’s easy to see why scientists have spent so much time excavating these spaces.

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It seems that humans are drawn more and more to these caverns in hopes of unlocking the secrets that have been left untouched for thousands of years. Perhaps we dream of answering some of the deeper questions of humanity. Or maybe we wonder about the world that has brought us into being...

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Vogelshacht and Lampreschtsofen

With many of the world's caves being so expansive in their own right, it's hard to imagine two caves being connected together. But explorers did just that. In a Poland-led exploration, the Lamprechtsoften-Vogelshacht caves were united as one, and together they plunge 5,354 feet underground.

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Wikimedia Commons via Sebastian Grünwald

The intricate and expansive system can be found near Salzburg, Austria, and promises a whole world of unknowns for exhibitionists. Many believe that the cave goes much deeper than what's been discovered. But until explosives are employed to clear the way, its true depth remains a mystery.

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Royston Cave's Secret Past

The Royston Cave can be found in South East England, just over 40 miles outside of London's city center. It is a man-made dome-like structure that dates back to the Middle Ages. And while its location lies in plain sight, its backstory remains largely unsolved and unaccounted for.

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Homer Sykes / Contributor via Getty Images

The cave's interior is covered in markings that have been likened to Pagan and religious roots. Although no official theory has been confirmed, historians and researchers alike highly suspect that the space was once occupied by the Knights Templar. Some even believe the markings hold clues to the Holy Grail!

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Unexplained Inhabitants of the Panxian Cave

We've learned about critters who have made the most inhospitable caves their home under the ground. But these habitat conundrums aren't only confined to the world's deepest caverns, they also apply to caves high above the ground. And in the Panxian Cave in China's mountainous region, scientists are looking for answers.

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Wikimedia Commons via The History Trust of South Australian, South Australian Government

Researchers exploring the caves came across multiple samples of both rhinos and stegodons (ancient relatives of the elephant): Not exactly the species that come to mind while exploring a cavern that's over a mile up in the sky. And since coming across the remnants, scientists have been scrambling for answers.

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Mystical Powers of the Cornwall Caves

With many of the world's caves dating back thousands of years, it doesn't surprise many that their origin stories have been lost over the ages. But it does leave scientists and historians searching for clues and hidden meanings. And the Caves of Cornwall are no exception. Tourists have had strange experiences while visiting.

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Graham Stone/Shutterstock

From bizarre noises to unexplained glowing orbs, guests have had their fair share of jaw-dropping moments in the cave's interior. It has prompted a look into the possible mystical significance of the cave. And with the cavern going back to 500 B.C., there sure is a lot of ground to cover.

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Ancient Footprints

High up in the Carpathian Mountains, footprints dating back 36,500 years have shaken the archeological community and prompted a great deal of speculation and wonder. The Transylvanian region is no stranger to mystery and folklore, thanks to the story of Count Dracula, but these markings have stirred a different kind of buzz.

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Wikimedia Commons via Momotarou2012

The prints were first discovered back in 1965 and pointed to a single-child family from roughly 15,000 years ago. But thanks to the radiocarbon measurements of fossils found close by, the markings were more accurately dated to 36,500 years. But, efficient dating brought more questions than answers...

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Yucatan's Hidden Underwater World

Roughly 66 million years ago, an enormous asteroid crashed into the modern-day region of the Yucatan Peninsula in Mexico. It resulted in a megatsunami, an aquatic force that obliterated around 120 miles of the Earth's surface and turned into a series of sinkholes. They would later be worshiped and used by the Mayans.

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Wikimedia Commons via Haakon S. Krohn

The ancient civilization believed that the sinkholes, known as cenotes, were sites of worship, and often used them as a place of great sacrifice. Dead bodies, gold, and jewelry were all thrown into the waters in hopes of blessing the people with good fortune. Now, the water provides the peninsula's residents with drinking water.

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The Mustang Caves' Many Lives

Tucked away in the Himalayas is a jaw-dropping cave system with a multi-layered past. The cliff pictured below is home to roughly 10,000 man-made caves. Exploration started in the 1990s and was headed by Nepali archeologists and researchers from the University of Cologne. And before long they discovered human remains.

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Wikimedia Commons via Ummidnp

After some serious digging, researchers have sectioned the caves' past into three distinct periods. In 1000 B.C., they were used as tomb sites. And in the 10th Century, they were used for refuge from ensuing violence. By the Middle Ages, they were utilized as places of meditation and surveillance. They're still occupied today.

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The Re-Discovery of the Caynton Caves

A seemingly normal rabbit's hole in an agricultural field led to one of England's many caves dating back to the 18th or 19th Century. The Caynton Caves had been sealed up but were rediscovered years later in a twist that brought a great deal of attention to the small town in the Shifnal.

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Wikimedia Commons via Richard Law

Folklore enthusiasts believed that the cavern was once home to the Knights Templar in the 17th Century. However, Historic England dates the grotto to the centuries following, thus debunking the connection to the famed military group. One thing's for sure: This cave has a story worth uncovering.

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Marcel Loubens Cave's Lone Skull

Back in 2015, a group of archeologists made a shocking discovery deep in the Marcel Loubens Cave. The group of researchers found the skull of a 24 to 35 year-old woman from roughly 3630-3380 B.C. Dating back to Europe's Copper Age, burying the dead in caves was fairly common, so what was so special?

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Wikimedia Commons via Langcliffe

Well, her skull wasn't accompanied by any other bones. So, how did it get there? According to the PLOS One publication, natural causes are to blame. From extreme rainfall to changes in the Earth's core, resulted in the skull making its way down to the cave's floor.

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Ancient Roman Swimming Pool

Out off the coast of Italy in the Tyrrhenian Sea lies a hidden gem. The Blue Grotto, or, in Italian, Grotta Azzurra proves to be a sight that defies the physics of light. Deep within the cave's structure, sunlight still manages to light the crystal clear waters, illuminating the whole cave in a glowing blue light.

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Wikimedia Commons via Langcliffe

And the cave's history is just as bright. During the Roman times, it's believed that the Blue Grotto on the island of Capri was used as Emperor Tiberius' personal swimming pool. In fact, statues dating back to that time were found at the bottom of the waters, including that of Roman sea Gods Neptune and Triton.

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