The Sahara Desert, covering most of North Africa, is the largest desert in the world. From north to south the Sahara is between 800 and 1200 miles and is at least 3000 miles from east to west. Due to the massive size of the Sahara, Africa is split into two regions that which lies above or forms part of the Sahara and the rest of Africa south of the Sahara. On the west, the Sahara is bordered by the Atlantic Ocean and on the east by the Red Sea and to the north are the Atlas Mountains and Mediterranean Sea.

Over 25 percent of the Saharas surface is covered by sand sheets and dunes. There are numerous rivers that originate outside of the Sahara but then enter the Sahara through underground waterways or by contributing to sources of surface water

The Saharas climate consists of basically two sub climates. A dry subtropical climate in the north and a dry tropical climate in the south. The dry tropical climate is generally characterized by mild, dry winters, a hot dry season just before the rainy season, and an annual temperature cycle. The dry subtropical climate, however, is characterized by annually high temperature ranges, cold winters, hot summers and two rainy seasons. There is a narrow strip in the western portion of the Sahara, along the coast, which generally has cool temperatures compared to the rest of the Sahara because of the influence of the cold Canary Current.

The Sahara is sparsely covered with various types of vegetation ranging from grasses, shrubs and trees in the highlands.

Some of the mammal species found within the Sahara is the gerbil, jerboa, Cape hare, the desert hedgehog, Nubian wild, spotted hyena, common jackal, sand fox, and the slender mongoose. The Sahara also contains over 300 species of migratory bird populations along with water and shore birds and various other types of birds. Some of the most common birds are ostriches, raptors, secretary birds, and guinea fowl.Numerous types of reptiles including frogs, toads and crocodiles can be found within the Saharas lakes and pools of water, while lizards, chameleons, skinks, and cobras are to be found among the dunes and rocks. Among the reptiles in the Saharas rivers and pools can be found snails, brine and algae shrimp.

The Sahara Desert covers over 3.5 million square miles and has only 2.5 million inhabitants roughly 1 person per square mile which is one of the lowest population densities on earth.