By locals, this smoldering crater called Darvaza Gas Crater or more well-known as the 'Gates of Hell'. These craters can be seen from a distance of several kilometers.
This is not a natural phenomenon, but rather the result of industrial accidents. In 1971, a Soviet drilling rig accident on an underground cave that stores natural gas in large quantities. It causes the ground to collapse and the whole rig drilling into it. Toxic natural gas leaking from the hole.
To overcome the potential environmental disaster, the Soviets set up a hole. The crater is not stopped burning since then.