Olduvai Gorge, the archaeological site also known as "The Cradle of Mankind”, 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 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.