The main branch of the East African Rift system, an ancient geological feature where the action of earthquakes and volcanoes created ideal conditions for burying and preserving bones. Many early hominid fossil sites have been discovered in the Great Rift Valley. In the north, the rift is occupied by the Jordan River, the Dead Sea, and the Gulf of Aqaba. It continues southward along the Red Sea and into the Ethiopian Denakil Plain to Lakes Rudolf (Turkana), Naivasha, and Magadi in Kenya. It continues through Tanzania southward through the Shire River valley and Mozambique Plain to the coast of the Indian Ocean near Beira, Mozambique.