The Western Desert is mostly rocky desert, though an area of sandy desert, known as the Great Sand Sea, lies to the west against the Libyan border. The desert covers an area of 262,800 sq miles (680,650 km2) which is two-thirds of the land area of the country.[1] Its highest elevation is 3,300 ft (1000m) in the Gilf Kebir plateau to the far south-west of the country, on the Egypt-Sudan-Libya border. The Western Desert is barren and uninhabited save for a chain of oases which extend in an arc from Siwa, in the north-west, to Kharga in the south.