Tanzania officially the United Republic of Tanzania (Jamhuri ya Muungano wa Tanzania), is a country in eastern Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands at the Indian Ocean to the east; Mozambique and Malawi to the south; Zambia to the southwest; and Rwanda, Burundi, and the Democratic Republic of the Congo to the west. Mount Kilimanjaro, Africa's highest mountain, is in north-eastern Tanzania.
The very first humans known lived in Pliocene Tanzania 6 million years ago. The genus Australopithecus ranged all over Africa 4-2 million years ago; and the oldest remains of the Homo genus are found near Lake Olduvai. Following the rise of Homo erectus 1.8 million years ago, mankind spread all over the Old World, and later in the New World and Australia under the species Homo sapiens. Homo sapiens also overtook Africa and absorbed the older archaic species and subspecies of humanity. One of the oldest known ethnic groups still existing, the Hadzabe, appears to have originated in Tanzania, and their oral history recalls ancestors who were tall and were the first to use fire, medicine, and lived in caves, much like Homo erectus or Homo heidelbergensis who lived in the same region before them.