the site's limestone caves, including the sterkfontein caves, were where fossils were found. a 2.3-million year-old fossil "australopithecus africanus" (nicknamed 'mrs. ples') was found in 1947 by robert broom and john t. robinson. the find followed the 1924 discovery of the juvenile "australopithecus africanus" skull, 'taung child', by raymond dart, at taung in the north west province of south africa, where excavations still continue.