One of the most peculiar man-made craters exist nowadays in the city of Dervaza in the Ahal province of Turkmenistan. The extraordinary site could be reached by driving 160 miles to the middle of the Karakum desert, north from the capital city Ashgabat.
This is where Soviet scientists initiated the exploitation of the natural gas-rich area. In 1971 they set up oil rigs and other drilling equipment to effectively harvest the rich gas fields beneath. Unfortunately, the drilling became so excessive that eventually the ground beneath started to collapse. There were no casualties from the accident but all the equipment and the scientists camp were lost and buried beneath the ground which formed a large crater about 230 feet in diameter.
Afterwards there were immense quantities of released methane gas into the atmosphere which turned out to be a huge environmental problem for the local population. The scientists then decided against extracting the gas from underneath which would have involved using extremely expensive methods. Instead, they chose to just light it on fire and burn it off believing the burning process would take no more than a few days. As it soon turned out they were very wrong. They created an eternally burning crater which melts mud and spits orange flames.
The crater, which was later called the “Door To Hell”, became a major tourist attraction in Turkmenistan and today, over 40 years since it was first lit, it still continues to burn.