It runs westwards from the headwaters in the Natal Drakensberg for 2250km to the Atlantic, plunging magnificently into the granite Augrabies gorge close to the Namibian border (in exceptional seasons the flow is greater than that of better-known Victoria Falls on the Zambezi River far to the north) before embarking on its last, desolate leg into the sea. Its tributaries include the Caledon and the Vaal, which is actually longer than the Orange but less voluminous. The Orange drains almost the entire plateau-47% of the country. Nowhere is the Orange River more impressive than at the Augrabies Falls, which ranks among the world's greatest cataracts on a major river. 

The Augrabies Falls National Park was established to preserve this natural wonder. The mighty Orange River is the Northern Cape Province's most important asset, which provides the basis for a healthy agriculture. The Northern Cape is a place of vast arid plains with outcroppings of haphazard rock piles. The cold Atlantic Ocean forms its western boundary There are vast tracks of bleak, shimmering semi-desert, which contrast dramatically with lush vineyards filling the Orange River's fertile valleys. The massive body of water meanders like a lacklustre spider through a giant valley of its making, the gossamer lines of its web threading themselves through and between the massive islands defying its erosive powers. Once the border of the Cape Colony, the Green Kalahari was South Africa's Wild West and many rogue and brigand, including the notorious Scotty Smith, sought refuge from the law in its far spaces and on the river's islands.