Uruq Bani Ma'arid is a protected area in southern Saudi Arabia, located on the western edge of the Rub' al Khali (Empty Quarter), the largest sandy desert in the world. The protected area is divided into three sections; a core nature reserve; a zone where controlled grazing is permitted; and a hunting zone.'Uruq Bani Ma'arid is in an area in which the Arabian oryx used to live before it became extinct in the wild. The reserve has been chosen for the reintroduction of oryx that have been bred in a captive breeding programme. It has also been selected as being suitable for the re-establishment of herds of Arabian sand gazelle (Gazella subgutturosa marica), mountain gazelle (Gazella gazella) and ostrich (Struthio camelus), all of which have historically inhabited the area.