South Africa's 'cradle of humankind' caves reopen to public

A simple sign leads visitors to the somewhat hidden entrance to the Sterkfontein Caves. The site of early human fossils, not far from Johannesburg in South Africa, has been a UNESCO World Heritage Site since 1999. In addition to archaeological artifacts, evidence of the upright gait of Australopithecus afarensis has also been found here.

Stairways lead visitors fairly comfortably into the dark and damp caves, but they still need a bit of courage and fitness. Visitors may have to crawl through narrow, dark tunnels or crouch to get through some tight spots.

Tour guide Keneth Mawete ducks his way through the entrance. The name "Sterkfontein" means "strong spring" in Afrikaans. Tourists are guided through the cave system from this point onward.

This replica shows what representatives of the Australopithecus afarensis, which lived in what is now Sterkfontein, might have looked like. "Lucy," seen here, was discovered in Hadar, Ethiopia, in 1974 and is around 3.2 million years old. Her name comes from the Beatles song "Lucy in the Sky with Diamonds," which was playing at the researchers' camp when the skeleton was found.

The caves are also known as the "cradle of humankind," as this region has provided some of the oldest evidence for the existence of the ancestors of modern humans. This includes "Little Foot," an almost complete skeleton of an early hominid estimated to be more than 3 million years old — a sensation in paleoanthropology.

A reproduction of the Australopithecus prometheus "Little Foot" can be viewed at the museum at the visitor center in Krugersdorp. The excavation took 15 years, as the bones were embedded in very hard dolomite rock and had to be very carefully uncovered by hand in the narrow and difficult-to-access cave structure.

The entire cave system is more than 47 kilometers (29 miles) long; visitors can only enter a small, secure area. No major accidents have been documented to date, but there have been situations during excavations in which geologists or palaeoanthropologists have been trapped or needed safety ropes to escape.