Mrs. Ples is the popular nickname for the most complete skull of an Australopithecus africanus ever found in South Africa. Many Australopithecus fossils have been found near Sterkfontein, about 40 kilometres (25 mi) northwest of Johannesburg, in a region of Gauteng (part of the old Transvaal) now designated as the Cradle of Humankind World Heritage Site. Mrs. Ples was discovered by Robert Broom and John T. Robinson on April 18, 1947. Because of Broom's use of dynamite and pickaxe while excavating, Mrs. Ples's skull was blown into pieces and some fragments are missing. Nonetheless, Mrs./Mr. Ples is one of the most "perfect" pre-human skulls ever found. The skull is currently held at the Ditsong National Museum of Natural History in Pretoria.