The Door to Hell (also known as the Crater of Fire or the Darvaza Crater) is a natural gas field in Derweze, Turkmenistan, that collapsed into an underground cavern in 1971.
Geologists reportedly set it on fire to prevent the spread of methane gas, and it has been burning continuously since then.
The crater, a popular tourist attraction, is around 100 feet deep with a diameter of roughly 225 feet. (GILES CLARKE/GETTY IMAGES)
A sinkhole that opened up and swallowed eight classic and historic Corvettes at the National Corvette Museum is seen Feb. 12, 2014, in Bowling Green, Ky. (MICHAEL NOBLE JR./AP)
A Los Angeles firefighter looks under a fire truck stuck in a sinkhole on Sept. 8, 2009, in the Valley Village neighborhood of Los Angeles. (NICK UT/AP)
A massive sinkhole on Rideau Street that knocked out power to the majority of downtown Ottawa, Ontario, is seen on June 8, 2016. (CHRIS ROUSSAKIS/AFP/GETTY IMAGES)
Workers prepare to pull vehicles from a sinkhole in the South Deering neighborhood of Chicago on April 18, 2013. Three vehicles were swallowed by the 15-foot-deep hole, leaving one driver hospitalized.(SCOTT OLSON/GETTY IMAGES)
Workers are seen on Nov. 9, 2016, by a giant sinkhole that appeared in the middle of the bustling business district of Fukuoka, Japan. (STR/AFP/GETTY IMAGES)
A sinkhole that opened a few days earlier in Natal, Brazil, is seen on June 22, 2014. The sinkhole, caused by recent rains, swallowed cars and damaged the homes of some 150 families living in a poor neighborhood in the northern Brazilian city that was one of 12 hosting World Cup matches. (ANTONIO CALANNI/AP)
The rear portion of a residential home is shown consumed by a sinkhole on Nov. 14, 2013, in Dunedin, Fla. (LUKE JOHNSON-POOL/GETTY IMAGES)
City officials in December 1995 survey a 60-foot-deep sinkhole that swallowed two homes in San Francisco’s exclusive Sea Cliff district and forced the evacuation of nine others. The hole measured approximately 200 feet by 150 feet and the fire department said it was probably caused by a broken sewer pipe. (GEORGE NIKITIN/AP)
A car sits in a sinkhole caused by a broken water main on Dec. 3, 2010, in Chevy Chase, Md. (LOGAN MOCK-BUNTING/GETTY IMAGES)
Employees install barricades around a collapsed building by a sinkhole at Summer Bay Resort near Walt Disney World on Aug. 12, 2013, in Clermont, Florida. (GERARDO MORA/GETTY IMAGES)
A vehicle is seen in a sinkhole as Debbie Baker-Star drives a school bus to pick up stranded people following Superstorm Sandy on Oct. 31, 2012, in Seaside Heights, N.J. (JULIO CORTEZ/AP)
A sinkhole created by Tropical Storm Agatha covers a street intersection in downtown Guatemala City on May 30, 2010. (STR/AP)
Workers inspect a Fairfax County school bus that collapsed into a residential street in Annandale, Va. A broken water main was to blame, and no injuries were reported. (IAN WAGREICH/THE WASHINGTON POST/GETTY IMAGES)