The Cradle of Humankind is a 180-square-mile site northwest of Johannesburg, home to the oldest hominid fossils ever found.

The Maropeng Visitor Center contains a small museum that explores the history of the area. On display are several fossil examples of mankind's earliest ancestors, as well as hands-on science exhibits, and a collection of photographs and artifacts.

The Sterkfontein Caves are also on this site, and they alone have provided a third of all early hominid fossils ever found. This includes the extraordinarily complete "Little Foot," an Australopithecus Prometheus skeleton. 

The caves contain an underground lake that has never been fully explored - the last time an expedition was launched to chart it, it lead to a diver's death. Tours are offered several times daily.