If you ever happen to visit Central Asia's Karakum Desert in Turkmenistan, you will witness a strange but breathtaking sight - A giant hole in the middle of the desert aglow with a fire that never seems to go out - And the fact is, that it has not gone out for the last forty years at least. However, this phenomenon, which has become a minor tourist destination, is not a natural wonder but the result of an accidental excavation.

In 1971, a group of Soviet geologists were drilling the ground in the area looking for natural gas and oil reserves when suddenly, the ground surface collapsed revealing a 230ft. diameter cavern, filled with hazardous methane gas.

Fearing that it would be toxic for the people living in the nearby village of Derweze, the scientists decided to try burn the gas off by setting it on fire - That was, 40 years ago. Turns out that cavern seems to have an incessant supply of the gas, which keeps the spectacular flames going night and day - a sight that can be seen for miles.

While the locals call the burning cavern 'The door to hell', it has definitely put the otherwise arid land onto a list of must-see tourist sites. Thanks to the gases emitted, visitors can only spend about 5 minutes around the area, but it is so unique that many people do take the time to make the journey to the burning hole that lies 260 kilometers north of Turkmenistan's capital, Ashgabat. Having said that, in 2010, the president of the country did order it be covered up and shut down and while it has not happened yet, it could very well be a possibility, in the near future.

Situated in Central Asia, the sparsely populated 350,000 sq.km wide Karakum Desert makes up about 80-90% of the Republic of Turkmenistan. Once covered by the sea, today the area is characterized by long hot dry summers where the temperature can range from 79°F near the Caspian Sea, (the largest enclosed inland body of water) to a high of 93°F, in the interior.

However, unlike other deserts, the Karakum does receive enough rainfall to allow for nomadic pastoralism. Also, thanks to water drawn in from the nearby Murghab and Hari Rivers, as well as, the Karakum Canal - The largest irrigation canal in the world - the area is able to sustain even crops like cotton. Also, as evidenced by the seemingly unlimited supply of gas in the Derweze cavern, the Karakum is home to large underground reserves of natural gas, oil, as well as, sulfur.

This is not the first time underground fuel reserves have resulted in inextinguishable fires. The once bustling coal mining town of Centralia, in east-central Pennsylvania is now an abandoned ghost town, thanks to a 50 year-old fire that is showing no signs of abating.

Resources: Britannica.com, journeygeek.com,dailymail.co.uk