In the hot, expansive Karakum desert in Turkmenistan, near the 350-person village of Derweze, is a hole 328 feet wide that has been on fire for over 40 years. Locals know the crater as "The Gates of Hells". Its glow can be seen for miles around.
The Gates of Hell were created in 1971 when a Soviet drilling rig accidentally punched into a massive underground natural gas cavern, causing the ground to collapse and the entire drilling rig to fall in. Having punctured a pocket of gas, poisonous fumes began leaking at an alarming rate. To head off a potential environmental catastrophe, the Soviets set the hole alight. The crater hasn't stopped burning since.
The Soviet drilling rig is believed to still be down there somewhere, on the other side of the "Gates of Hell."