Swartkrans is a fossil-bearing cave designated as a South African National Heritage Site, located about 32km from Johannesburg. It is located in the Cradle of Humankind World Heritage Site and is notable for being extremely rich in archaeological material, particularly hominin remains. Fossils discovered in the limestone of Swartkrans include Telanthropus capensis (a variety of Homo erectus), Paranthropus and Homo habilis. S. V. Drobyshevskiy identifies remains of Homo naledi with Telanthropus. The oldest deposits present at the site are believed to be between 1.9 and 2.1 million years old.Noted paleontologist Robert Broom was a frequent digger. He was followed by C. K. 'Bob' Brain, whose excavations at the site inspired his book The Hunters or the Hunted? in which he demonstrated that instead of being bloodthirsty killer apes, the hominin fossils found at the site were themselves victims of predation by big cats. Originally, it was believed that Dinofelis was responsible for such killings, though recent evidence suggests that hominids were likely the victims of Megantereon or leopards based on carbon isotope ratios taken from each predator.