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 northern 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.
Olduvai Gorge is one of the most important paleoanthropological sites in the world and has been instrumental in furthering the understanding of early human evolution. This site was occupied by Homo habilis approximately 1.9 million years ago, Paranthropus boisei 1.8 million years ago, and Homo erectus 1.2 million years ago. Homo sapiens is dated to have occupied the site 17,000 years ago.
This site is also significant in showing increased developmental and social complexities in hominins. Evidence of this is shown in the production and use of stone tools, which indicates the increase in cognitive capacities. Evidence also indicates the practices of both scavenging and hunting, which are highlighted by the evidence of gnaw marks predating cut marks, and comparisons on percentages of meat versus plant in the early hominid diet. Furthermore, the collection of tools and animal remains in a central area is evidence of increases in social interaction and communal activity.