While drilling in 1971, geologists tapped into a cavern filled with natural gas. The ground beneath the drilling rig collapsed, leaving a large hole with a diameter of 70 metres (The Gates of Hell). To avoid poisonous gas discharge, it was decided to burn it off. It’s still on fire. Check video :
Erta Ale is a continuously active basaltic shield volcano in the Afar Region of northeastern Ethiopia. It is the most active volcano in Ethiopia. Erta Ale is 613 metres (2,011 ft) high, with one or sometimes two active lava lakes, one of only five in the world, at the summit. These lava lakes occasionally overflow on the south side of Erta Ale. It is notable for being the longest existing lava lake, present since the early years of the twentieth century (1906). It is located in the Afar Depression, a badlandish desert area spanning the border with Eritrea, and the volcano itself is surrounded completely by an area below sea level, making it one of the lowest volcanoes in the world.
Erta Ale’s last major eruption was on September 25, 2005, which killed 250 head of livestock and forced thousands of nearby residents to flee. Additional lava flow activity took place in August 2007, forcing the evacuation of hundreds and leaving two missing. Not much is known about Erta Ale, as the surrounding terrain is some of the worst on earth and the native Danakils are not friendly.
The name of the volcano means “smoking mountain” in the local Afar language and its southerly pit is known locally as “the gateway to hell”. It has recently been mapped by a team from the BBC using three dimensional laser techniques. These types of volcanoes are very rare and have searingly hot temperatures. For that reason the laser was used, as it has the capability to map any surface. Read more at wikipedia and sverop .