The NCA, a World Heritage Site and Biosphere Reserve, was established in 1959 as a multiple land use area; designated to promote the conservation of natural resources, safeguard the interests of indigenous residents and promote tourism. Man and his ancestors have lived in the Ngorongoro eco-system for more than three million years. The main features of the NCA include the Ngorongoro Crater, The Serengeti Plains (short grass plains) that support migratory wildlife counted in the millions and the the Northern Highland Forest Reserve. Other areas of interest are the archaeological sites located at Oldupai Gorge as well as Olkarien Gorge and Nasera Rock located in the eastern reaches of the area. Unlike the national parks, it’s possible to participate in walking safaris within the NCA and several extinct volcanoes and smaller craters provide exciting opportunities for day hikes at altitude. The jewel in Ngorongoro’s crown is a deep, volcanic crater— the largest un-flooded and unbroken caldera in the world. About 20 kms across, 600 meters deep and 300 sq kms in area, the Ngorongoro Crater is a breath taking natural wonder.