Sterkfontein (Afrikaans for Strong Spring) is a set of limestone caves of special interest in paleoanthropology located in Gauteng province, about 40 kilometres (25 mi) northwest of Johannesburg, South Africa in the Muldersdrift area close to the town of Krugersdorp.

[4][dead link‍] Modern excavation of the caves began in the late 1890s by limestone miners who noticed the fossils and brought them to the attention of scientists.

The caves yielded the first adult Australopithecine, substantially strengthening Dart's claim that the skull known as the Taung Child (an Australopithecus africanus) was a human ancestor.

[5] In 1997, a nearly complete skeleton of a second species of Australopithecus (StW 573) was found in the caves by Ronald J. Clarke; extraction of the remains from the surrounding breccia is ongoing.

It is estimated to be around 2.6–2.2 Ma based on a combination of uranium-lead dating and palaeomagnetic analysis[6] and belongs to a second species of australopith, Australopithecus prometheus.

[12] The palaeomagnetic analysis [6] remains the most credible age estimate based on the current data as it included work on both sediments and speleothem.