The planet we live on is sometimes bewildering. From mind-bending natural structures to tiny creatures who have beaten the odds by surviving and thriving under confounding circumstances, the world can be a mysterious place. There are phenomena on Earth that are just so alien, scientists are still scratching their heads thousands of years after discovery. Here are a few strange locations no one has quite figured out to this day.

Eternal Flame Falls

Eternal Flame Falls with flame and waterfall
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Everyone knows that fire and water don't mix, yet in western New York State it doesn't seem to matter. Eternal Flame Falls in the Shale Creek Preserve continues to baffle geologists. Visitors can see a brightly burning flame in the waterfall and there is no reasonable explanation why. While most recognized "eternal flames" in other parts of the world have been found to be the result of natural gas release under hot temperatures, the rock beneath Eternal Flame Falls is relatively cool.

Legend has it Native Americans lit the flame thousands of years ago. Researchers, including scientist Arndt Schimmelmann from Indiana University, remain puzzled on how such a flame is produced without an adequate heat source. Geologists still hope to identify the cause in the future.

The Cave of Crystals

Inside of Cave of Crystals with person standing
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Buried beneath the mountains near Naica, Mexico is a magical place you might associate with a science fiction movie. The Cave of Crystals was discovered accidentally by two miners in the year 2000 and the world was immediately intrigued. The subterranean space is filled with massive, white crystals nearly 39 feet long and 3 feet wide jutting everywhere in the horseshoe-shaped cave. The beautiful, mind-boggling discovery continues to draw scientists from all parts of the globe.

Researchers know how the crystals were formed (nucleation) but are still perplexed by their sheer scale and the continuing growth of the crystals. The Cave of Crystals is as dangerous as it is awe-inspiring. Visitors are requires to wear special cooling suits as well as limit their time in the cave.

Stone Spheres of Costa Rica

Stone sphere in Costa Rica
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When the United Fruit Company in Costa Rica was searching for new ground to plant banana trees in the early 1930s, they came across some odd stone spheres. The almost perfectly-rounded rocks were like nothing they had seen before. The largest of the stones were over six feet in diameter though not all of them were the same size. The workers rolled the strange orbs out of the way to finish their job.

Years later, archaeologists began to study the spheres trying to determine the origin. Hundreds of the gabbro-formed balls have been discovered since the fruit company first stumbled across them all those years ago. The predominant theory is that the smooth mystery rocks were man-made by the Pre-Columbian cultures of Costa Rica but no one knows exactly why to this day.

Namibian Fairy Circles

Unexplained circles in Namib Desert
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In the grasslands of southern Africa's Namib Desert are unexplained "fairy circles" that have kept scientists baffled for years. The barren patches range in size from 10 to 65 feet and are surrounded by short grassy plants forming a circular pattern. Namibian local legend claims the circles were created by the gods who carelessly left their giant footprints to mark the red dirt. A view of them from satellite imagery on Google just might give credence to the claims.

Scientists, of course, beg to differ with the locals though they can't seem to agree on an explanation. Some say the fairy circles were formed when termites cleared the vegetation around their underground habitat to promote natural rainwater reservoirs. Others believe it was caused by the plant life competing for much-needed water. No one has settled the issue yet though they continue to try.

The Hessdalen Lights

Lights over mountain in Norway
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Something weird started happening in the skies of the small central Norwegian town of Hessdalen almost forty years ago. People were seeing hundreds of strange lights where only stars should be. It began in 1981 and it wasn't long before UFO hunters converged on the village to see what they could see. They weren't disappointed. The sometimes colored lights randomly illuminated the night sky at least 20 times a week during its heyday.

The unusual phenomenon is still occurring but with less frequency than the good old days. Scientists have many viable explanations including the presence of cosmic rays or piezoelectricity but all fall short of a satisfying and proven explanation. For UFO enthusiasts, that's okay.

Plain of Jars

Large stone jars in grassy field in Laos
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Few visitors find their way to the remote plains of Xieng Khouang Plateau in Laos, but there's a reason they should. Hundreds of enormous, ancient stone jars dot the landscape like a giant's forgotten toys. Some of the jars have artful reliefs carved into them and scientists can only speculate as to their purpose. The urns likely date back to the Iron Age when the use of objects made of iron was widespread. Yet the jars were created with clay, dung, sandstone, and sugar, and baked in huge kilns.

The Plain of Jars was designated as a UNESCO historical site in 2019 and remains, for the most part, an archaeological mystery. No one knows for sure how the heavy jars were dragged from the quarry and arranged into their present groupings.

Patom Crater

Crater in Siberian forest
Credit: Dmitry Semenov/ CC BY 

Patom Crater is a 131-foot high geological formation in Siberia no one even cared about until recently. Russian scientists finally took notice and discovered a crater that looked similar to an eagle's nest with an egg inside. Locals stayed clear because they thought it possessed evil powers. Scientists were quick to suggest the strange crater was caused by a meteorite but the lack of meteorite fragments anywhere in the area brought them back to the drawing board. The possibility of a UFO landing was discussed and soon discarded.

Some geologists have hypothesized the uncommon formation came from under the earth rather than above it. This theory involves a magma explosion caused by steam from beneath the surface. Patom Crater remains one of Siberia's greatest mysteries.

Nazca Lines

Massive Nazca Lines drawing
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From the sky, they look like drawings of animals and people drawn carefully by children's hands. But the Nazca Lines of Peru are sprawling representations covering at least 170 square miles of arid coastal land. The ancient geoglyphs are thought to date back as far as 500 B.C. Scientists have finally figured out how the Nazca created this giant artwork so long ago. "All of these figures were created by removing the black stones that cover the land, thereby exposing the white sand beneath," researchers explain. It doesn't get much cooler than that.

The purpose of these prehistoric lines continues to elude anthropologists and archaeologists alike. Could they be linked to the constellations of the night sky or were they drawn as a part of a water-conjuring ritual? No written records have ever been found, freeing us all to imagine what this ancient art might represent.