A ride through the dust-devils and scorched earth of the Karakum Desert delivers you to Darvaza Crater, the apocalyptically fiery hole in the earth that more than justifies its nickname – the Door to Hell. 60 metres wide and 20 deep, a first look into the crater is an incredible, surreal, experience – there, in the middle of nowhere, countless vicious fires rage beneath you, the seething mass of the pit hypnotic as sulphurous fumes fill the nostrils and the flaming heat beats upwards to meet the baked desert air. Seemingly straight from the pages of Revelations, that this spectacle is man-made comes as a shock. An underground cavern filled with natural gas which Soviet geologists decided to burn off; their presumption was the fire would last a few days. It’s been raging ever since. It’s at night that Darvaza Crater is perhaps most memorable, the campsite (at a safe distance!) giving a front-row view onto what must rank as one of the world’s most extraordinary, and unlikely, man-made sights: the endless darkness stretching on forever except for the glowing crater, burning like the sun emerging through the earth’s crust.