On espeleovirtual you can read and watch photos & videos about a giant burning crater, which can be found in Darvaz, Turkmenistan, in the middle of Karakum Desert. Local people call it the “Gates of hell”. In 1971, people were searching for gas, when somehow they a big crater opened with collapse of the terrain, and poisoning gases come out of it. Scientist deicided to burn the dangerous gases, so they set it on fire, but it seems that the has flow from the hole is endless, because it is burning since nearly 40 years!