The country of Turkmenistan is made up of five Provinces, one of the largest being the Ahal Welayat which is situated in the central part of country. Ahal is almost completely desert (in fact Turkmenistan is 70 per cent desert) and has just 14% of the country’s population. This part of the country is also extraordinarily rich in natural resources.
It’s this rich abundance id natural resources that lead to the creation of the Hells Door. When Soviet scientists discovered a cache of oil reserves near the town of Derweze in the Karakun Desert, they started drilling almost immediately. But the drill rigging collapsed, creating a large crater and causing large amounts of methane being released. The scientists began to get concerned that the large amount of gases being released could be harmful so decided to try to burn it off and set it alight. They thought it would burn off within a few days.
That fire is still burning off the gases over 40 years later and quite the sight to see.