HARUJ AL-ASWAD, AL-

hilly basaltic plateau of central Libya. A startlingly black expanse (area 15,500 sq mi [40,150 sq km]), it rises out of the surrounding sand to 2,600 ft (800 m) and is crowned by a series of volcanoes, Qarat as-Sab'ah, attaining altitudes of 3,900 ft. Ancient lava streams run in all directions between sandy basins with grasses, bushes, and acacia groves appearing after the rains. The western edge breaks off sharply, while in the east, wadis (seasonal rivers) extend into the surrounding desert. The south is demarcated by the 'Unqud al-Yasirat, two lines of 40 volcanoes; an outcrop to the southeast contains the oasis of Waw an-Namus, which lies in the bottom of a crater 330 ft deep and 2 to 2 1/2 mi (3 to 4 km) in diameter. Three swampy lakes support reeds, palms, water hens, reptiles, and migrating birds. Mosquitoes, however, make the place uncomfortable for man, and it is visited only periodically by passing caravans in search of water.