Yanardag, meaning "Burning Mountain" in Azerbaijani, is one of the most unusual natural phenomena in the world. Located about 25 kilometers north of Baku, this hillside continuously blazes with natural gas flames. The flames have burned for centuries, possibly ignited by lightning strikes on the natural gas deposits. Local legends attribute the eternal flames to the mythical Baku Phoenix. The site has become a popular tourist destination, especially at night when the flames are most visible against the dark sky. No fuel is needed to keep the flames burning - they are completely natural and self-sustained. Scientists believe the flames will continue to burn as long as there are underground gas reserves.