Early human ancestors lived in what would become the Serengeti for 4 million years (Australopithecus afarensi). The Maasai people had been grazing their livestock in the open plains of eastern Mara Region, which they named "endless plains," for around 200 years when the first European explorer, Austrian Oscar Baumann, visited the area in 1892. The name "Serengeti" is an approximation of the word used by the Maasai to describe the area, "siringet", which means "the place where the land runs on forever".