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 earliest hominins; that is, the earliest of the human clade. As a result, the Depression is thought by some paleontologists to be the cradle of human evolution. The Depression borders Eritrea, Djibouti, and the entire Afar Region of Ethiopia. It contains the lowest point in Africa, Lake Assal, Djibouti, at 155 m (509 ft) below sea level.