Barsa-Kelmes has been terrorizing the locals since antiquity, with a series of creepy legends and ancient beliefs.
The ancient underwater city of Kitezh is shrouded in myths and mystery, but there are many indications this place really did exist before it was destroyed.
A destructive cosmic event has puzzled scientists for more than a century. Now scientists have revealed that it could have even ended the humanity.
They are so precisely cut that even a razor blade can't fit through their interlocking joints – a technology that didn't exist until centuries later.
A solar-powered balloon mission detected a repeating infrasound noise in the stratosphere. Scientists have no idea who or what is making it.
Some researchers think that Gigantopithecus could be the missing link between apes and humans, while others believe that it could be the evolutionary ancestor of the legendary Bigfoot.
The Dwarfie Stane, a massive piece of red sandstone, has been cut into a tomb that dates back 5,000 years. Despite countless attempts to solve the mystery of its origin, no one has been able to determine who created it or why it was built.
Gremlins were invented by the RAF as mythical creatures who break airplanes, as way to explain random mechanical failures in reports; an "investigation" was even conducted to make sure Gremlins didn't have nazi sympathies.
The sea serpents have been depicted as undulating in the deep water and coiled around ships and boats, putting an end to the life of seafarers.
Chupacabra is arguably America's strangest and most famous enigmatic beast that sucks animal blood.