Deep within the expansive plains of Turkmenistan’s Karakum dessert is a jaw-dropping phenomenon that keeps defying expectations.

Locals call it the “door to hell” and it's not hard to see why. The giant sinkhole, known more formally as the Darvaza gas crater, is an incredible 69 metres wide, 30 metres deep, and is constantly in flames.

Records of how it came to be are imprecise, but it is understood that Soviet geologists initially came across the site in 1971 and believed it was rich in oil. But shortly after they began drilling, the crater collapsed and began emitting noxious gases.
In an attempt to minimise the dangers of the gas, they set it alight with the expectation it would burn itself out in a matter of days. But the calculations appear to be way off, and the crater has been burning continuously for 45 years.

An alternative version dates the sinkhole’s collapse to the 1960s, and says it was set alight two decades afterwards, making an accurate timeline difficult to establish.

Much of Turkmenistan is rich in natural gas and there is little understanding on how long it will continue to burn. In 2010, President Gurbanguly Berdimuhamedow ordered that the hole be closed, but that doesn’t seem to have happened.

Canadian adventurer George Kourounis was the first known person to descend into the pit in 2013, and he described it to National Geographic, who partly funded his expedition, as “a coliseum of fire”.

“Just everywhere you look it's thousands of these small fires. The sound was like that of a jet engine, this roaring, high-pressure, gas-burning sound,” he says.

“And there was no smoke. It burns very cleanly, so there's nothing to obscure your view. You can just see every little lick of flame.”