The last of the Rift Valley Lakes (in Ethiopia), formerly known as Lake Rudolf, is Lake Turkana. It is located southwest of the Omorate within the Ethiopian and Kenyan Rift Valley and is the largest permanent desert lake as well as the largest alkaline lake in the world. Despite the climate being hot and dry, the lake supports a rich lacustrine wildlife. Predominantly volcanic rocks ring the lake and it has an active volcano for a central island. Three rivers, the Omo, Turkwel and Kerio flow into the lake but it has no outflow, so it only loses water to evaporation. Large numbers of Hominid fossils discovered in the Lake Turkana area have led anthropologists proclaiming it as the cradle of humankind.