Olduvai Gorge is a steep-sided ravine in the Great Rift Valley that stretches through eastern Africa. It is in the eastern Serengeti Plains in Arusha Region, Tanzania and is about 48 km (30 mi) long. It is located 45 km (28 mi) from the Laetoli archaeological site. The name is a misspelling of Oldupai Gorge, which was adopted as the official name in 2005. Oldupai is the Maasai word for the wild sisal plant Sansevieria ehrenbergii, which grows in the gorge
In the Ngorongoro Conservation Area is a site of our Neanderthal Man - the Zinjanthropus. In 1959, the Zinj skull was discovered by Dr. Leaky at the Olduvai Gorge. Zinjanthropus is believed to have lived 1.8 million years ago. In the 1970's, the footprints of animals and early hominids dating back 3.5 million years were found by Mary Leaky at Laetoli some 45 kms. South of Olduvai Gorge.
In 1974 some fossils of the hominid tooth were discovered, dating back 2.4 million years. Between half a million and a million years ago, "Homo Erectus", a type of man, wandered around making use of hand axes. Many such tools were found at Olduvai.
More than 150 different species of extinct mammals have been identified from the fossils, as well as many birds, reptiles, amphibians and fish. An on-site Museum explains the archeological significance of the discoveries. This area, it seems, is the "Cradle of Mankind".