One of Turkmenistan’s most unusual sights, the Darvaza Gas Craters are the result of Soviet-era gas exploration in the 1970s. The three craters are artificial. One has been set alight and blazes with an incredible strength that’s visible from miles away, while the other two contain bubbling mud and water. There have been rumors for years that the burning gas crater will be put out to enable gas exploration in the area, but so far still burning strong.