Ngorongoro is a pioneering experiment in multiple land use, as the park has the multiple purposes of integrating the protection of the local people with that of wild nature, the latter being divided into two separate biogeographical systems. The vast plains in the west and north are definitely a part of the Serengeti ecosystem, whereas the centrepieces of the other part are the breathtaking Ngorongoro crater, one of the natural wonders of the world. Amazingly, the crater floor is a natural sanctuary for almost all the large mammalian species essential to the East African plains. Its highlights include one of Tanzania’s most viable populations of the critically endangered black or browse rhino, and it is also here that the density of great predators, headed by hyenas and lions, is the highest in the world.