Cradle of Humankind

Olduvai Gorge — increasingly called Oldupai, closer to the Maa word for the wild sisal that grows there — cuts through layers of volcanic ash and lake sediment on the plains between Ngorongoro and the Serengeti. Because those layers were laid down in sequence and can be dated, the gorge preserves an unusually readable record of hominin fossils and stone tools. Louis and Mary Leakey worked here from the 1930s onwards; in 1959 Mary Leakey found the cranium now assigned to Paranthropus boisei, and fossils from the gorge contributed to the description of Homo habilis in the 1960s.

At Laetoli, south of the gorge, a team led by Mary Leakey uncovered trails of footprints preserved in volcanic ash in the late 1970s. They are generally dated to approximately 3.6 million years ago and are usually attributed to Australopithecus afarensis. They are widely cited as evidence of upright walking at that period. The original trackway was reburied to protect it and is not open to visitors; casts are displayed in museums.

Much later, and in a different register, come the painted rock shelters of Kondoa, inscribed as a UNESCO World Heritage Site in 2006. Their images of people, animals and abstract forms are thought to span at least two thousand years, with some panels possibly far older. Dating rock art is difficult and estimates vary between researchers; many of the sites remain important to local communities today, and interpretations of the images are not settled.