There are many mysteries on Earth, and each one is more fascinating than the last. Over the decades and centuries, there have been a number of strange objects that humans have found. What’s so interesting is that we cannot explain them.
We have made strides in science, and continue to make more each day, but still, some things are unexplainable. These baffle and intrigue us, and of course, make us scratch our heads. What are these objects and what is their purpose? We might never know.
If you enjoy a good mystery, here are 30 items that have been found on Earth, that cannot be explained.
1. The Atacama Skeleton
In 2003, a man by the name of Oscar Munoz stumbled upon this six-inch-long skeleton in the Atacama Desert. The skeleton’s strange alienesque features caused quite a buzz among those still hopeful for proof of extraterrestrial life. After extensive analysis, it was determined that the skeleton does in fact, belong to a human. Scientists could confirm this with absolute certainty through DNA extraction. Naturally, this probed further mystery regarding how and why a human could be so small.
After successfully confirming that the Atacama was not an alien, researchers had a different mystery to unravel. Scientists immediately began working on plausible theories that would explain a six-inch-long human skeleton.
Initially, the skeleton was believed to be a mummified aborted fetus. Alternative opinions believe the skeletal remains belonged to a young child with severe deformities. The mystery remains unsolved but continues to intrigue mystery fans.
In the 13th century, this mysterious book was believed to contain all human knowledge. Click ‘Next!’
2. The Codex Gigas
The Codex Gig, otherwise known as the “Devil’s Bible,” is the largest medieval manuscript in the World. Weighing in at over 165 pounds, this mysterious book was believed to contain all human and medieval knowledge.
Within this book, you will find a version of the old testament, the new testament, and several secular works. The manuscript was produced in the 13th century and is steeped in rich history and mystery, all of which, cannot be explained.
Besides the enormous dimension of the Codex Gigas, the book is fashioned in animal skins, which would have required the use of 160 animals.
The text within the book suggests a single author, although the scribe remains unknown. Perhaps, the most prominent feature is the large illustration of the devil in the middle of the book. Today, the book remains one of the most mysterious Ancient texts in the World.
Can a sword be made with metal using technology that hasn’t been created yet? Click ‘Next’ to find out.
3. Ulfberht Viking Swords
Imagine finding a sword that was virtually unbeatable in battle, and crafted from the purest metals on Earth. The Ulfberht Viking Swords is just that; it was the ultimate weapon.
These swords were found between 800 and 1,000 A.D, and the discovery has since confused the archeological community. All the swords were made of a pure metal, yet the technology used is unknown.
Since the discovery of the swords, experts have attempted to recreate the manufacturing process, but remain baffled. One theory regarding these swords suggests that the methods and materials come from the Middle East. There is even talk of Norse gods having an impact on the craftsmanship. Some believe that an alien race might have helped in their creation, and others believe that a time traveler is the key to their existence. Do you have any ideas?
Even with today’s modern technology, it is still a mystery how blacksmiths made these swords, and they are almost impossible to reproduce
Is this an Ancient Roman artifact, trans-oceanic travel, or a myth? Keep clicking, then decide for yourself.
4. The Tecaxic-Calixtlahuaca Head
The Tecaxic-Calixtlahuaca head was discovered in an undisturbed pre-colonial burial ground in Mexico City. It has been traced back to the years 1476 and 1510 A.D., but it looks nothing like anything from that era.
Perhaps the most mysterious thing about the head is that it looks like artwork from the Roman Empire. Many people believe it is an Ancient Roman artifact, and some hypothesize that the artifact could be evidence of trans-oceanic contact.
The Tecaxic-Calixtlahuaca head was sent to Germany for thermos-luminescence testing, which found that the relic was produced between 184 BC and 616 AD. This definitively proved that the relic was much older than the grave it was found in.
Further studies analyzed the stylings and determined that the head fit within Roman 3rd-century artwork. Although strides were made, there are still many questions that remain unanswered about this small artefact.
How can a one-inch doll challenge history and evolution. Keep clicking to find out.
5. The Nampa Figurine
In 1889, well workers found a tiny artifact, which appeared in the human form. Little did they know, this clay figurine would become a baffling mystery that would challenge history and evolution for years to come.
The artifact was formed in clay in a 300-foot well, placing its age far beyond the arrival of man. Further analysis dated it at two million years old, thereby, challenging evolution as we know it. Though we know our ancestors lived before the two million year mark, we have no evidence that these hominids had the skills to do this.
Many skeptics claim that the Nampa Figurine is a hoax, these disbelievers believe that the figurine is a recent artifact, which was placed as a joke.
Scientists and respected archeologists in the fields tend to disagree with this assumption based on the fine craftsmanship of the relic. The artifact remains controversial, and many believe it points to evidence that humans existed in America during the Pilo-Pleistocene age.
After over a century of research, historians are still baffled by this unexplained mystery. Click ‘Next’ for more.
6. Sumerian King List
This four-hundred-year-old cube tablet was found in the early 1900s, and since its discovery, it has puzzled historians. The Sumerian King List is an ancient artifact that features Sumerian and neighboring dynasties, reign lengths, locations of kingships, and Kings of Sumer.
What is so mysterious about the King list is the list combines pre-dynastic rulers with historical rulers, some of which are mythical.
The relic also shares shocking similarities with the book of Genesis. Many historians have noted that the Sumerian King List speaks of “the flood that swept over the Earth.” It also speaks of eight kings who reigned for a period during the flood. There is writing on each of the four sides of the cube.
Following the great flood, the King List provides an account of kings who recorded for shorter time periods, indicating the same decreasing longevity found in the Bible.
Many people believe this cloth offers physical proof of Jesus Christ. Keep clicking to learn more.
7. The Shroud of Turin
Do we have physical evidence that Jesus actually rose from the dead? If you believe this next item, we might. Many people believe that the Shroud of Turin provides physical evidence of the crucifixion, death, and resurrection of Jesus Christ. The authenticity of the shroud is a constant source of debate among theologians.
The Shroud of Turin is a piece of linen cloth, which bears the image of a man, believed to be Jesus of Nazareth. Despite several different recovery methods, the image on the Shroud remains muted.
The shroud, believed to be the burial cloth of Jesus, measures in at 14 feet by 3.5 feet. Upon detailed analysis, the image features a man who has been tortured, beaten, and crucified.
Also, the cloth features over 100 whip marks, which coordinate with the wrists and feet, as well as a possible crown of thorns. The similarities between this item and the Biblical story are remarkable, making it the most analyzed religious relic in the World.
Can a prehistoric bird be making a comeback? Keep clicking to see what science discovered!
8. The Mount Owen Moa Claw
A group of archeologists in New Zealand, made a frightening discovery over three decades ago, which led to a major backlash. This resulted in an unexplained mystery that is still confusing people everywhere.
What they found looked like a massive dinosaur claw, but what was so mysterious and a little frightening, was that the claw was intact, and so well preserved that it appeared as if the animal had recently died.
Upon further analysis, the claw was identified as the 3,300-year-old mummified remains of an Upland Moa. Since the first discovery of the Moa bone, several others have been found, including many mummified remains. The remains include soft tissue still attached, which further heightens the mystery. Why? Because the Moa has been officially extinct since the 1400s, though sightings have been reported over the centuries.
The moa bird has been mentioned as a potential candidate for revival through cloning efforts now that numerous remains have now been extracted. It is estimated that it would take about 50 years to do this based on modern technology.
These caves date back 2,000 years and in China, are considered the ninth wonder of the Ancient World. Click ‘Next.’
9. The Longyou Grottoes
The Longyou Grottoes are a massive group of underground caves located in the Zhejiang province of China. In China, the caves are considered the ninth wonder of the Ancient World and they remain a mystery that continues to perplex experts from a variety of research fields.
The caves were originally discovered in 1992, which led to the discovery of an additional 36 grottos in an overwhelming 30,000 square meters.
Researchers have yet to find out why, how, or who built the caves and in the process of this research, they found more mystery.
The construction of these grottoes would have required over a million cubic meters of stone; however, there is no recorded evidence of construction or the materials. Additionally, all the cave walls are chiseled in a parallel line, requiring heavy manpower.
Could this mysterious archeological site prove that Vikings arrived before Columbus? Keep clicking ‘Next’ to find out!
10. L’Anse aux Meadows
Standing at the northern tip of the island of Newfoundland in Canada, you will find a mysterious archeological site known as L’Anse aux Meadows. The site was first discovered in the 1960s and is considered the most famous Viking settlement in North America.
Many people believe that this settlement proves that the Vikings arrived in America at least 500 years before Columbus. This is mysterious because as far as other historical evidence goes, we didn’t know that these people ever go that far inland.
After further investigation into the village, archeologists found the foundation of eight small homes and other signs of long-term living. Around the excavation site, researchers found a variety of precious objects, all of which told a story.
While this evidence points to the Viking and Norse arrival on the settlement, it does nothing to clear up the mystery surrounding pre-Columbus trans-oceanic travel. We still don’t know much about that, at all!
This “out of place” artifact is thought to be a contribution to alien life. Click “Next” for more.
11. The Baigong Pipes
The Baigong pipes are believed by many conspiracy theorists to be evidence of alien life. This series of pipes is made of iron and 30 percent silicon dioxide. The pipes are centuries old, which leads people to believe that a lone drifter created them. But, as you might expect, there are other theories, too.
There is, of course, the theory that the pipes were made by aliens, who arrived in China, on the Baigong Mountains thousands of years ago. Afterall, anything that can’t be explained is due to aliens, right?
So, why are these pipes so mysterious? Besides, the whole alien conspiracy theory, they are in an area of China, which is known to have never contained people. Also, the pipes are clear of debris even though they are centuries old.
Although Chinese researchers were sent to the site in 2002, and continue to work on unraveling the mystery of these pipes, it remains unexplained.
Is this an Ancient spark plug, or just a rock? Keep clicking.
12. The Coso Artifact
The Coso Artifact was found 4,300 feet above sea level in Owens Lake, CA, and is considered an out-of-place artifact.
The object was first discovered covered in a piece of hard clay in 1961 and has since been a mystery. If the ancient relic was in fact, what people thought it was, it could provide scientific evidence of a historical anomaly.
After the discovery of the Coso artifact, it was clear that it was much more than a rock. In fact, it is believed to be an ancient spark plug, created long before the technology was available.
Within the layer of rock, was a two-millimeter shaft of bright metal with no signs of oxidation or corrosion. This is so puzzling because you know that most metal always rusts eventually. Further studies led researchers to believe that this is some form of machinery.
Can a collection of stones contain evidence of advanced technology and depiction of prehistoric dinosaurs? Click ‘Next.’
13. Ica Stones
In the early 1930s, a cultural anthropologist found hundreds of andesite stones containing depictions of prehistoric dinosaurs. The burial stones were estimated to be between 500 and 1,500 years old.
The mysterious stones feature images that depict open-heart surgeries, brain transplants, and some sexually graphic content. The most surprising of the etchings featured representations of a stegosaurus, brontosaurus, and other prehistoric dinosaurs. This is quite puzzling, as we have no other evidence that man lived at the same time as dinosaurs.
Each of the Ica stone depicts a different scene, which leaves room for a lot of interpretation. The mystery shrouding these artifacts prompted scientists to unravel the scenes behind each narrative.
While there are no definitive answers, some researchers believe that ancient technology belonged to an extraterrestrial race. This unknown race referred to as the Gliptolihic Man, is believed to have coexisted with dinosaurs, then genetically engineered into modern man.
Scientists have dedicated 200 years of research into this next item but cannot explain it. Click “next,” to see it.
14. Roman Dodecahedrons
Over 200 years of research has been dedicated to understanding the origin and function of these stone objects. To date, with over 100 of these artifacts discovered, the mystery surrounding them is no closer to being solved.
The Roman Dodecahedron are objects with a geometrical shape, usually ranging between four and 11 centimeters in size. The greatest mystery behind these artifacts is how they work, what they do, and why exactly they were made.
Since there is no documentation regarding the construction of the Dodecahedrons, its origin is left to our imagination.
The most accepted theory states that these are Roman measuring devices, more specifically, they were used as to measure ranges on the battlefield. It could also be a religious relic, or simply, just a geometric shape.
We all know that Columbus discovered America, right? Well…perhaps not. What? Keep clicking, ‘Next!’
15. The Gate of the Sun
Located in Bolivia, the Gate of the Sun is a 13,000-foot astrological and archeological mystery. The gate, also known as Pumapunku, forms a part of a monument group known as Tiwanaka. This archeological site is so complex, the engineering techniques puzzle even the Aztecs. Additionally, the structure dates back to the time before Columbus.
The stone blocks located on the site have no chisel marks, or signs of craftsmanship, which makes their shape and design a complete mystery.
The mystery behind the Gate of the Sun only gets stranger. The stone used to build the temple, came from two separate mines, one was 10 miles away, and the other was 50 miles away. How did the ancients get the stone that far without modern tools?
The stone hedge shows signs of producing blocks weighing upwards of 400 pounds, which would require the use of many stones. The process used to build them also suggested modern technology.
Is the lost city of Atlantis real? If so, could it be in Japan? Click ‘Next.’
16. The Yonaguni Monument
Historians, researchers, and even scuba divers have sought to find Atlantis, the lost underwater city for centuries. When divers discovered the Yonaguni Monument in 1987, many people believed they had found it.
The Yonaguni Monument is a set of 100,000-year-old ruins submerged off the coast of Japan. Many experts have attempted to identify the site, which has only led to controversy and more unanswered questions.
After researchers, had attempted to uncover the identity of the ruins, they found what appeared to be a giant archway. The arch included intricate carvings, paved streets, and grand staircases.
While scientists persist in their research, the belief is that the remnants are from an old city that existed nearly 10,000 years ago that has sunk into the sea. Other theorists believe in a massive underwater world, which scientists are still trying to unravel.
The tallest and most famous stone in history was abandoned mid-project. Take a guess why, and click, ‘Next.’
17. An Unfinished Obelisk
You can find the Unfinished Obelisk still in its original location, in Rome, where it would have weighed in at over 1150 tons if fully complete. The massive relic is the tallest and most famous stone in history, which is still partially attached to bedrock.
Unfortunately, the obelisk never reached completion, as the project was abandoned after the creators discovered cracks within the granite.
Although the Unfinished Obelisk remains in the original location, its history remains unknown. Since the project was abandoned, no one laid claim to its craftsmanship, leaving the construction techniques unknown.
The base of the Obelisk stands nearly 14 feet high, raising questions as to how someone could erect something so enormous from a hillside. When comparing other Obelisks in history, the achievement required the collective efforts of several pharaohs.
Can stones fit perfectly together like a puzzle without any sealant? Keep reading!
In the city of Peru, you can find a complex stone wall known as Saksaywaman. The precision used to create the wall is found nowhere on Earth, which has puzzled scientists for decades.
Each stone fits with rounded corners, interlocking shapes, and are tightly fit together without a single form of sealant. The shape of each stone perfectly fits with the adjacent stone like a perfect puzzle.
Scientists have been working hard to uncover the stone-cold truth about this ancient wall, and they have developed some theories. They believe a softening solvent derived from a mysterious plant like liquid.
Another theory suggests that the heat from the sun has caused the minerals in the rocks to separate. While science has yet to figure it out, visitors worldwide enjoy marveling at its beauty.
Can a small Japanese figurine manifest sympathetic magic believed to cure illness? Click “Next,” to see.
19. Dogu Figurines
The Dogu figurines are a mystical product left over from Japan’s Jomon period, which is the earliest era in Japan’s history. According to Japanese writings, these figurines are part Earth, and part spirit.
So, how could a clay figurine arouse such power? It is hard to say, but one thing is for certain; these humanoid figurines are strangely hypnotic and somehow arouse emotions within people.
The people of the Jomon era were known for creating some of the earliest pottery in the world, but the reason behind these figures is a continued mystery. The most plausible theory behind the Dogu points to evidence of religious culture or shamanic rituals.
There are four forms of Dogu figures, each of these figures all share the form of the woman figure; there is no evidence of a male Dogu figure, however.
This mythical island was home to Poseidon, God of the Sea. But is it mythical? Click ‘Next!’ to see.
19. Gobekli Tepe
In Turkey, you will find the oldest known archeological site, which provides significant evidence of advanced construction. Gobekli Tepe is a series of temples constructed over 13,000 years ago, during the Neolithic period. The site is well preserved and appears to have been created with advanced tools and methods.
Per historians, the Neolithic man was not skilled in hunting or construction; thus, many theories suggest that beings from another planet aided in the building of the temples.
After archeologists had studied the site of the Gobekli Tapes, evidence suggests that the temples were most likely used as a site for religious gatherings. Although that mystery was unraveled, historians are still unable to figure out how ancient man built the 40-60 ton pillars using primitive tools.
Also, after the site was built over 12,000 years ago, it was active for 3,000 years, only to be meticulously covered up around 8th century BC.
This site comes from a period that even respected archeologists know very little about. Click ‘Next’ to see it.
This historical site, known as Stonehenge, was built in the Neolithic Age, a time that even respected archeologists know very little about.
The structure is comprised of stones known as “sarsens,” which are 30 feet tall and 25 tons. The smaller “bluestone,” weigh up to four tons. Stones of this size would require transportation from over 140 miles away, and it is unknown why, or how, ancient people did this.
The mystery into how and why Stonehenge was built has baffled the minds of archeologists for decades. After digging around the site, researchers have come up with a few plausible theories.
According to their results, Stonehenge may have been used as a burial site, or as a ceremonial site. It also could have been a final resting place for royalty, a religious destination, or a memorial erected to connect with distant ancestors.
Among the collection of Dead Sea Scrolls, this one is profoundly different. Do you know why? Click “Next,” to see.
21. The Copper Scroll Treasure
The Dead Seas Scrolls are a collection of over 900 different texts found in the Qumran Caves, all of which contain deep historical and biblical significance. Each of the scrolls was written on parchment, except the copper scroll treasure.
Besides this significant difference, the copper scroll treasure is not a literary work like the others. It provides a list of locations in which silver and gold is buried.
Researchers and biblical scholars wanted to know why the copper scroll was so different from the other sea scrolls, and it is still widely debated today.
Some researchers believe that the copper scroll belongs to the Qumran community. Another theory states that the treasure belonged to a temple destroyed by Nebuchadnezzar. A third widely explored possibility is that the copper scroll is the product of a hoax.
This gilded case was built by the Israelites 3,000 years ago. Click “Next,” to see what it was used for.
22. The Ark of the Covenant
Over three thousand years ago, the Israelites built a lavish gilded case for transporting the Ten Commandments. Some people believed that the Ark was the throne of God and when the Ark traveled somewhere, God was present.
The entire Ark was covered in gold and inside it contained the Ten Commandments, Torah’s scroll, and Aaron’s rod, which was carried on a 40-year trip across the desert.
The Ark of the Covenant was rumored to be very powerful, although no one could see or touch it. Anyone traveling with the Ark was protected and provided for along the journey with the relics life-sustaining properties. As quickly as the Ark would sustain life, it would destroy it and perform impossible miracles.
Many archeologists have searched for signs of the Ark, and some even believe they have unearthed proof that it exists.
If you like the Lord of the Rings, you must see this next mystery. Click ‘Next’ to see why.
23. The Hobbits
In 2003, scientists uncovered stone tools, animal remains, and the first fossil of a species known as Homo Floresiensis. After analysis of the specimen, researchers determined that the bones belonged to a 30-year old adult female, who lived nearly 17,000 years ago. The specimen had a complete skull, several bones, feet, hands, and stood only 3.5 feet tall, which earned the species the nickname, “the hobbit.”
Initial dating of the remains placed the species living anywhere from 17,000 to 74,000 years ago, however, analysis of the tools ages the species much further.
With this information, the mystery only deepens, prompting scientists to believe that this could be a separate species that belonged to an extinct human. Other theories link the species to chimpanzees, and some believe it is a distinct species of its own.
Can an entire civilization disappear without leaving any evidence of their decline? Keep reading to find out.
24. The Lost Maya
The collapse of the Mayan civilization is one of the greatest unsolved mysteries of our time. Many researchers have tried unsuccessfully to explain how an entire civilization can collapse without leaving any evidence of their downfall.
The Mayan civilization was developed by the Mayan people and is well known for their writing system in pre-Columbian America. They are also known for their contribution to art, mathematics, architecture, and astronomy.
Around the eighth and ninth century, something unknown caused the Mayan civilization to shake and fall. Slowly, each of the cities was abandoned and the entire region collapsed.
Thankfully, some of the Mayans written records survived the collapse allowing researchers the ability to study the documents. The most probable theories regarding the decline are over-farming, disease, and warfare.
Did scientists unearth a relic from your favorite Bible story? Keep clicking to find out.
25. Noah’s Ark
In the Bible, God gave Noah specific instructions regarding the dimensions of Noah’s Ark, which would hold two of every animal to protect against the Great Flood.
When you read about Noah’s Ark, you probably did not realize that it was such a great mystery, or that it would cause a worldwide search known as “arkology.” As it turns out, many people believe that Noah’s Ark is real and have set out on expeditions in search of it.
The team located seven wooden partitions buried 13,000 feet above sea level, near Mt. Ararat, which is where many people believe is the Arks final resting place. This discovery came in addition to a few other unsubstantiated claims including a discovery of the ark in Iran and China.
Why are archaeologists puzzled by this stone structure? Click ‘Next.’ for more.
26. Underwater Structure in the Sea of Galilee
The Bible continues to arouse mystery and this time it is in the Sea of Galilee where a giant stone structure is puzzling archeologists. The cone shaped structure is estimated to weigh over 60,000 tons.
So, why is this stone so mysterious? Well, besides the enormous weight, the diameter is over 230 feet, which is just half as tall as Stonehenge. Researchers are struggling to define the purpose of a structure so tall in the middle of Galilee.
Divers went down to the site to investigate it up close and personal, which revealed that the structure is made of basalt with no apparent construction pattern.
The research and investigation has unearthed a few theories. It could be an ancient city that researchers are calling “Bet Yerah” or “Khirbet Kerak.” Another theory leads scientists to believe that it could be a burial site of some kind.
Did the first emperor of China spend 38 years constructing a mausoleum for his burial site? Keep clicking ‘Next.’
27. Qin Shi Huang’s Tomb
The first emperor of China, Qin Shi Huang, is encased within a mystery that historians and researchers have been itching to unearth for years. The emperor died on September 10, 210 BC.
He lies buried within a tomb on a hill in China, which was constructed over the course of 38 years, underneath a truncated pyramid. The burial site has never been excavated and he has not been disturbed for thousands of years.
Many people believe that the tomb holds the answers to many historical mysteries, but the chances of ever seeing inside the mausoleum are slim. The hill where the emperor is buried has never been excavated, and there is no technology in the world available that could open it.
For over four decades, archeologists have been attempting to excavate the site to uncover the secrete of the emperor and per researchers, they will be digging for centuries.
How can an enormous stone and coral reef island exist with no record of construction? Click “Next” to see.
28. The City of Nan Madol
In Micronesia, off the island of Pohpnpei, there is an ancient city built entirely on a coral reef called Nan Madol. It is the only of its kind in existence and a pure work of art, consisting of 100 stone and coral platforms among artificial islands.
Building the island required the use of several enormous rocks, and a huge undertaking in construction and transportation. Yet, there are no records of construction in existence.
Scientists theorize that the island was built around the 5th to 11th century AD as a ceremonial or ritual burial site for ruling chiefs.
Despite the mystery that still shrouds the site, it is recognized worldwide among historians and archeologists as a masterpiece of creative genius. This recognition is due to the islands preserved habitat, and ceremonial architecture.
There are theories, but no one agrees…why is there a high concentration of labyrinths on this island? Keep clicking.
29. The Bolshoi Zayatsky Labyrinths
On a very remote island in the White Sea of Russia, you will find a very mysterious, unexplained concentrations of labyrinths. These maze-like passages are the highest concentration found on planet, and the reason and purpose are completely unknown.
The labyrinth is one of the strange symbols on the planet with a thousand-year history of fascinating and confusing scientists.
It is only at the location in Bolshoi Zayatsky Island that you will find 14 stone labyrinths within a 0.4 km area. They are remarkably well preserved, and although they have been well documented, no one knows their specific purpose.
There are a few explanations for labyrinth’s; one belief states that they were built to trap fish. Another school of thought believes they reflect the sun and the moon, and some believe it is a symbol of wholeness.
You will not believe what appeared in the middle of Siberia. It is a true mystery. Click ‘Next.’
30. The Siberian Sinkholes
Scientists are baffled about a massive crater that appeared out of nowhere in the middle of Northern Siberia, near Yamal. The giant black hole is hundreds of feet wide and just appeared one day. Scientists have ruled out a meteorite strike, but the cause of the hole remains unknown.
While speculation among the extra-terrestrial community is a buzz regarding a possible UFO, it turns out it could be the area’s geology.
So, there is a hole in the middle of Siberia for no known reason, and scientist’s everywhere want to know why. Well, according to one polar scientist in Australia, it could be the result of a melted polar formation, known as a “pingo.”