Saharan Atlas, part of the chain of Atlas Mountains, extending across northern Africa from Algeria into Tunisia. The principal ranges from west to east are the Ksour, Amour, Ouled-Naïl, Zab, Aurès, and Tébessa (Tabassah). Mount Chélia (7,638 feet [2,328 m]) is the highest point in northern Algeria, and ash-Shaʿnabī (5,066 feet [1,544 m]) is the highest peak in Tunisia. Iron ore is mined near Mount Ouenza, and there are extensive phosphate deposits near the town of Tébessa, both in Algeria.