The Afar Triangle is a geological depression caused by the Afar Triple Junction, which is part of the Great Rift Valley in East Africa. The region has disclosed fossil specimens of the very earliest hominins; that is, the earliest of the human clade, and it is thought by some paleontologists to be the cradle of the evolution of humans; see Middle Awash, Hadar. The Depression overlaps the borders of Eritrea, Djibouti and the entire Afar Region of Ethiopia; and it contains the lowest point in Africa, Lake Assal, Djibouti, at 155 m below sea level.
The Awash River is the main waterflow into the region, but it runs dry during the annual dry season, and ends as a chain of saline lakes. The northern part of the Afar Depression is also known as the Danakil Depression. The lowlands are affected by heat, drought, and minimal air circulation, and contain the hottest places of anywhere on Earth.
The Afar Triangle is bordered as follows: on the west by the Ethiopian Plateau and escarpment; to the north-east by the Danakil block; to the south by the Somali Plateau and escarpment; and to the south-east by the Ali-Sabieh block.