The Hoggar Mountains, also known as the Ahaggar, are a highland region in central Sahara, or southern Algeria, along the Tropic of Cancer . They are located about 1,500 km south of the capital, Algiers and just west of Tamanghasset. The region is largely rocky desert with an average altitude of more than 900 metres (2,953 feet) above sea level. The highest peak is at 3,003 meters . The main city nearby the Ahaggar is Tamanghasset, built in a desert valley.