The crater known as "Door to Hell" has been burning for decades.
In Turkmenistan, a natural gas crater has puzzled scientists and tourists for decades. The Darvaza crater, popularly known as "Door to Hell", ignited in 1971. It has become a renowned tourist attraction and a unique geological phenomenon. Despite efforts to extinguish it, the fiery pit in the Karakum Desert still burns brightly, drawing visitors from around the globe to witness its otherworldly spectacle. In all these years, just one man has entered the 230-foot-wide, 100-foot-deep pit with expected temperature of 1,000 degrees Celsius to obtain gas readings and soil samples.
George Kourounis climbed into the "Door to Hell", that belches out methane, in 2013. According to National Geographic, Mr Kourounis prepared for two years for the expedition and got only 17 minutes to collect the samples.
"That 17 minutes is etched pretty deep into my brain. It was so much scarier, so much hotter and bigger than I thought," he said.
He reached the bottom of the pit, held by a series of ropes and encased in a heat-reflective suit, and using self-contained breathing apparatus and a custom-made climbing harness that wouldn't melt from extreme heat.
"When you're dangling in the middle you just feel like a piece of laundry on the line, drying out. I was looking around and it looked like a doorway to hell - you realise that if something were to go wrong and fall that you're dead from a fall," he said about the expedition in a video released later.
The expedition raised awareness about the crater around the world, and Mr Kourounis' photo inside it became one of the most widely shared images on the internet.
The origin of "Door to Hell"
National Geographic said it's not known how the crater came into existence, but several theories have floated around for decades. One such tale says engineers of erstwhile Soviet Union were drilling in the area sometimes in the 1960s when the earth crumbled beneath them, opening up the huge hole.
The engineers believed to have lit the methane gas, hoping it would quickly burn away. But the blaze continues to burn till date.
The 'Door to Hell' is a popular spot among tourists and gives Turkmenistan huge revenue.