The slow burn (((with great photo)))
Mt Wingen Australia underground coal fire first noted by westerners around 01828, but it is predicted that it has been burning for over 6000 years.
â€œFossil Reactorsâ€ are naturally occurring underground fission reactions in Uranium deposits of Oklo Africa, estimated at around 1.7 billion years old.
â€œDoor to Hellâ€ (pictured above) Near Darvaz in Uzbekistan, burning since ~01972
Some tire fires have lasted several years
(Via Long Views)