evidence: The Sperrgebiet, or forbidden territory, lies in the south-western corner of Namibia. Famous for its diamonds, the area is bordered by the Orange river in the south and the Atlantic Ocean to the west. The northern boundary was established at the 26°S line of latitude, whereas the eastern boundary parallels the coast c.100 km inland. The IBA includes the Namibian side of the Orange river mouth (adjacent to IBA ZA030). Largely uninhabited, the only towns in the Sperrgebiet are Oranjemund on the southern coast and Lüderitz on the northern coast. The Sperrgebiet is an extremely arid zone, encompassing the northern extremity of the winter-rainfall portion of the Namib desert. It is the windiest region in southern Africa. The only permanent water in the area is the perennial Orange river. The northern coastal plain is rocky and holds various sandy bays; the southern shores, intensively mined for diamonds, are reconstituted sandy beaches. The major part of the remaining area comprises sand and gravel-plains with low isolated hills. In the centre and north of the park, dune sand and sand-sheets predominate, the most prominent area being Obib dune-field which rises to 500 m.