Sterkfontein (Afrikaans for Strong Spring) is a set of limestone caves of special interest to paleo-anthropologists located in Gauteng province, about 40 km (23 miles) Northwest of Johannesburg, South Africa in the Muldersdrift area close to the town of Krugersdorp. The archaeological sites of Swartkrans (Afrikaans for Black Cliff) and Kromdraai (Afrikaans for Crooked Turn) are in the same area. Sterkfontein is a South African National Heritage Site and was also declared a World Heritage Site in 2000 and the area in which it is situated, was named the Cradle of Humankind. The Sterkfontein Caves are also home to numerous wild African species including Belonogaster petiolata, a wasp species of which there is a large nesting presence.