Located between the Ngorongoro Conservation Area and Serengeti National Park in Tanzania, Olduvai Gorge consists of a thirty-mile steep-sided ravine that is 295 feet deep. Part of the Great Rift Valley, Olduvai is a misspelling of the local Maasai word, Oldupai for the wild sisal plant that grows in the region. More importantly, paleoanthropological evidence from 2.1 million to 15,000 years ago found in the gorge have yielded the fossil remains of more than 60 hominids and provided scientists with the most continuous known record of human evolution as well as information about the development of stone tools. It was named a UNESCO World Heritage Site in 1979.

While Wilhelm Kattwinkel and Hans Reck had noticed fossils and stone tools at the site more than a hundred years ago, World War I interrupted any further investigation until Louise Leakey and his wife, Mary came to the gorge in 1929. Convinced that the site held vital information on human origins, Louis began excavations. Their work along with the prior work of Raymond Dart and Robert Broom in South Africa convinced the scientific world that humans evolved in Africa.