Part of the Cradle of Humankind World Heritage Site near Krugersdorp, Sterkfontein Caves is a limestone cave system first flagged as geologically significant in the late 1890s, though decades of lime mining in the early 1900s destroyed many fossils before their scientific value was understood. Serious excavation began under Robert Broom in 1936, leading to the 1947 discovery of ‘Mrs Ples,’ a roughly 2.1-million-year-old Australopithecus africanus skull. Researcher Ron Clarke later uncovered ‘Little Foot,’ a near-complete Australopithecus skeleton, first noticed in 1994-95 and fully excavated by 1997, and a 2022 Wits University study re-dated the deposits as around a million years older than previously thought. One of the richest hominid fossil sites in the world, the caves remain open for guided tours and continue to draw visitors and researchers from across the globe.