The Darvaza gas crater, also known as the Door to Hell or Gates of Hell, or, officially, the Shining of Karakum, is a burning natural gas field collapsed into a cavern near Darvaza, Turkmenistan. The floor and rim of the crater are illumined by hundreds of natural gas fires. The crater has been burning since the 1980s. How the crater formed is unknown, but engineers ignited the crater to prevent poisonous gases from spreading.