Yanarta (flaming rock) is the Turkish name of a geographical feature near the Olympos valley and national park in Antalya Province in southwestern Turkey. The location is 80 km southwest of Antalya. It is the site of dozens of small fires which burn constantly from vents in the rocks on the side of the mountain.
It is thought that these flames have been burning since the 4th century and sailors used them as beacons to navigate their ships. The mountain consists of two dozen vents, which are grouped in two patches on the hillside above the Temple of Hephaistos.
Directly below the fires are the ruins of the temple of Hephaistos, the Greek god who was associated with fire through his role as the blacksmith to the gods. To see the fires and the ruins, visitors must first go to the entrance at the foot of the mountain.
The vents emit mainly methane (87%). The rest is made of hydrogen (7.5-11%), nitrogen (2-4.9 %), light alkanes (0.57%), carbon dioxide (0.01-0.07 %) and helium (80 ppmv).
These vents represent the biggest emission of abiogenic methane discovered on land so far. The emissions do not have a volcanic origin, since methane is not related to mantle or magma degassing.
In ancient times sailors could navigate by the flames, but today they are more often used to brew tea.
The hike to reach the flames can be quite far and is best taken at night time, for an interesting view of the blue flames. Most people visit at night, when the fires are at their most spectacular.