The Sahara is the largest hot desert in the world, and the third largest desert behind Antarctica and the Arctic, which are both cold deserts. The Sahara is one of the harshest environments on Earth, covering 3.6 million square miles (9.4 million square kilometers), nearly a third of the African continent, about the size of the United States (including Alaska and Hawaii). The name of the desert comes from the Arabic word ṣaḥrāʾ, which means “desert.”
The Sahara is bordered by the Atlantic Ocean on the west, the Red Sea on the east, the Mediterranean Sea on the north and the Sahel Savannah on the south. The enormous desert spans 11 countries: Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and Tunisia.
The Sahara desert has a variety of land features, but is most famous for the sand dune fields that are often depicted in movies. The dunes can reach almost 600 feet (183 meters) high but they cover only about 15 percent of the entire desert. Other topographical features include mountains, plateaus, sand- and gravel-covered plains, salt flats, basins and depressions. Mount Koussi, an extinct volcano in Chad, is the highest point in the Sahara at 11,204 feet (3,415 m), and the Qattara Depression in Egypt is the Saraha’s deepest point, at 436 feet (133 m) below sea level.
Most of the people who live in the Sahara occupy the oases and the highlands on the desert fringes. Arabic-speaking peoples, including the Bedouin of Libya and the Chaamba of Algeria, live in the northern Sahara. On the northern and western edges of the desert are many groups of BERBERS. The largest Berber-speaking group within the Sahara is the Tuareg, who number between 500,000 and 1 million people. The Berbers and Tuareg have cultural and religious ties to Islamic, Arab-speaking northern Africa. To the east, in NIGER and northern Chad, live the Teda or Tubu peoples, whose languages and cultures are closely linked to those of sub-Saharan African groups.
Livestock herding and trade are the main economic activities of the Sahara. Desert dwellers raise camels, goats, and sheep, and in some oases they also grow gardens and date palms. The principal trade good is salt, either mined or obtained from evaporated water. Since ancient times, Saharans have traded salt for grain and other goods from the agricultural regions south of the desert. The Tuareg salt trade continues today, unlike most of the long-distance trade that once crisscrossed the Sahara. The major economic event of the 1900s in the Sahara was the discovery of mineral resources, particularly oil, phosphate, iron, uranium, and bauxite, the source of aluminum.