In every list of the most WTF things on this planet, this doorway to hell is on it. Burning since 1971, it’s 230 feet wide and was caused by a Soviet drilling rig, that accidentally hit a massive cavern full of natural gas.

The ground collapsed, the rig fell in and poisonous fumes started to leak out. To avoid an environmental catastrophe, they lit the pocket on fire, hoping to burn off the gas. 40 years later, it’s still going.