The “Door to Hell” is a natural gas field in Derweze, Turkmenistan, that collapsed into an underground cavern in 1971, becoming a natural gas crater.
Geologists set it on fire to prevent the spread of methane gas, and it has been burning continuously since then. The diameter of the crater is 69 metres (226 ft), and its depth is 30 metres (98 ft).
The site was identified by Soviet engineers in 1971. It was originally thought to be a substantial oil field site. The engineers set up a drilling rig and operations to assess the quantity of oil available at the site. When they instead found gas, the ground beneath the drilling rig and camp collapsed into a wide crater and disappeared.
Expecting dangerous releases of poisonous gases from the cavern into nearby towns, the engineers thought it best to burn the gas off. It was estimated that the gas would burn out within a few weeks, but it has instead continued to burn for more than four decades.
The crater was featured in a Die Trying episode titled “Crater of Fire”. Explorer George Kourounis became the first person to ever set foot at the bottom, gathering samples of extremophile microorganisms. The episode was broadcast on the National Geographic Channel on July 16, 2014
In April 2010, the president of Turkmenistan, Gurbanguly Berdimuhamedow, visited the site and ordered that the hole should be closed, or measures be taken to limit its influence on the development of other natural gas fields in the area. Turkmenistan plans to increase its production of natural gas, intending to increase its export of gas to many countries such as Pakistan, China, India, Iran,Russia, and Western Europe, from its present yearly production level to 225 billion cubic metres (7.9×1012 cu ft) in the next 20 years