A UNESCO protected World Heritage Site and an International Biosphere Reserve, the Ngorongoro Conservation Area is situated some 190 km. west of Arusha, between Lake Manyara and Serengeti National Parks. Covering approximately 8,292 square km, the Ngorongoro Conservation Area consists of the Ngorongoro Crater itself, the Olduvai Gorge and Ndutu, the Empakai crater and the Oldonyo Lengai Mountain. The Ngorongoro Conservation Area is a pioneering experiment in multi-purpose land use where people (the Maasai), their livestock and wildlife coexist and share the same protected habitat. Wild animals are protected as in the National Parks. The craters of Ngorongoro and Empakai are reserved exclusively for wildlife, while the rest of the Conservation Area is shared by wildlife, people and livestock. The Maasai, the main residents of Ngorongoro, are pastoralists who move widely with their herds of cattle, sheep, goat and donkeys in search of pasture and water. In recent years the Maasai have been encouraged to work on the land and supplement their traditional diet of milk and meat.