More than four decades ago over a remote part of the Karakum Desert, located in the far southern part of the former USSR, a fiery crater opened up and has been burning continuously ever since.
What makes this fiery crater so unique is that it's not volcanic, and it's not entirely natural either.
The Darvaza gas crater or “The Door to Hell” is a 230 foot wide burning hole in the earth located approximately 250 miles east of the Caspian Sea in modern day Turkmenistan. 
It's formation started in 1971 when geologist from the former USSR identified the area as a substantial oil field site. Soviet petrochemical engineers proceeded to set up a drilling rig and started drilling operations at the site when the ground gave way. The drilling rig dissappeared into the newly formed crater.
Fortunately no lives were lost in the incident, but large quantities of methane gas started leaking into the air posing a serious environmental problem and a potential danger to those in nearby villages. Fearing the release of more gas into the atmosphere, the engineers decided to light it on fire.
The remaining gas was expected to burn up in a matter of days or a few weeks. However, more than 40 years later, the gaseous pit is still burning!
On a dark night, the glow of the fiery crater can be seen from miles away and the smell of burning sulfur can be detected from a distance that becomes quite strong as you near the hot edge of the crater.
The Door to Hell has become one of Turkmenistan's few tourist attractions as it draws hundreds of adventure seekers each year out into the Karakum desert where summer temperatures can reach a blistering 120° without the help of the oversided Darvaza fire pit!
In April 2010, the president of Turkmenistan, Gurbanguly Berdimuhamedow, visited the site and ordered officials to find a way to put out the blaze for fears that the fire would draw off gas from other nearby drilling sites potentially damaging Turkmenistan's vital energy exports.
In an effort to energize the country's economy, Turkmenistan plans to increase its production and export of natural gas to portions of Europe and Asia in the coming years.
The Karakum Desert, where Darvaza is located, has one of the largest gas reserves in the world.
No word on when the famous Darvaza fire will be put out.
The Derweze (Darvaza) area in Turkmenistan is rich in natural gas. While drilling in 1971 geologists accidentally found an underground cavern filled with natural gas. The ground beneath the drilling rig collapsed, leaving a large hole with a diameter of about 70 meters. To avoid poisonous gas discharge, it was decided to burn the gas. Geologists had hoped the fire would go out in a few days but it has been burning ever since. Locals have named the cavern The Door to Hell.
