Dallol is a volcanic explosion crater (or maar) in the Danakil Depression, northeast of the Erta Ale Range in Ethiopia. It was formed during a phreatic eruption in 1926, and numerous other similar craters dot the salt flats nearby. These craters are the lowest known sub aerial volcanic vents in the world, at over 45 m (150 ft) below sea level.
The term Dallol was coined by the Afar people and means dissolution or disintegration describing a landscape made up of acid ponds (pH-values around 2) iron oxide, sulfur and salt desert plains. The area resembles the hot springs areas of Yellowstone Park but appears to be more wide-stretching.