series of separately channeled cataracts and rapids on the Orange River in arid Northern Cape province, South Africa. The falls, which form the central feature of Augrabies Falls National Park (established in 1966), occur where the Orange River leaves a plateau formation of resistant granite. The main fall of water is 305 feet (93 m); and the total drop is about 625 feet (191 m). At the bottom the depth of the plunge pool probably exceeds 140 feet (43 m). The width of the falls at floodtime extends over several miles with 19 separate waterfalls tumbling into a ravine 11 miles (18 km) long.