The huge, flaming hole that suddenly appeared in the northern Turkmenistan desert is believed to have been caused by a drilling accident that occurred more than 40 years ago. The blazing Darvaza Crater, commonly known as the Door to Hell, is a bizarre sight in the otherwise empty landscape today.

In November 2013, storm chaser and explorer George Kourounis went on an expedition to explore the crater’s 225-foot (69-meter) width and 99-foot (30-meter) depth for the first time. When he first sees the crater, it appears to be a scene from a science fiction film. In the middle of this vast desert, there lies a large, blazing pit with absolutely nothing else. When you’re downwind, you experience a tremendous heat blast that prevents you from even looking directly into the wind. You must use your hand to shield your face while standing at the edge of the crater. When you’re in the “colosseum of flames,” which Kourounis calls the crater, you feel incredibly small and defenseless.

Some say that the sinkhole was created by Soviet scientists, who set it on fire to release deadly gases when the ground beneath a drilling rig collapsed, though there are few facts on how it came to be. But the story that has been spreading online is slightly different from what the local geologists told Kourounis. Some of it remains a mystery.