The great mass of Egypt is located in Africa; the Sinai peninsula is the only portion situated in Asia and is separated from the rest of the country by the Suez Canal. Egypt N of Cairo is often called Lower Egypt and S of Cairo, Upper Egypt. The principal physiographic feature of the country is the Nile River, which flows from south to north through E Egypt for c.900 mi (1,450 km). In the far south is Lake Nasser, a vast artificial lake impounded by the Aswan High Dam (built 1960–70), and in the north, below Cairo, is the great Nile delta (c.8,500 sq mi/22,000 sq km). Bordering the Nile between Aswan and Cairo are narrow strips (on the average 5 mi/8 km wide) of cultivated land; there are broad regions of tilled land in the delta.
West of the Nile is the extremely arid Libyan (or Western) Desert, a generally low-lying region (maximum alt. c.1,000 ft/300 m), largely covered with sand dunes or barren rocky plains. The desert contains a few oases, notably Siwah, Farafra, and Kharga. In SW Egypt the desert rises to the Jilf al-Kabir plateau. East of the Nile is the Arabian (or Eastern) Desert, a dissected highland area (rising to c.7,150 ft/2,180 m) that is mostly barren and virtually uninhabited except for a few settlements along the Red Sea coast.
The Sinai peninsula is a plateau broken by deep valleys; Mount Catherine, or Jabal Katrinah (8,652 ft/2,637 m), Egypt's loftiest point, and Mount Sinai, or Jabal Musa (7,497 ft/2,285 m), are located in the south. Northern Sinai, largely a sandy desert, contains most of the peninsula's small population, which lives mainly in towns built around wells.