In 1971, Soviet geologists working in Turkmenistan set a crater on fire to prevent the spread of methane gas, expecting it would burn for a few days.

The hole has since been burning for over 52 years and is know as The Door to Hell.

https://video.nostr.build/d5b1b47a3e8e8910da47a20a30db06752b45f3422fed607e37ca3b9d1deedb2c.mp4