The physical features of Africa include the Sahara desert, Sahel, Ethiopian Highlands, savannas and rainforests. Some other major features are the Swahili Coast, Southern Africa, the Great Lakes and the Nile River.
The Sahara desert, one of the main geographical features of Africa, starts in the north of the continent with the Atlas mountains and moves south, covering more than eight million square miles and 25 percent of the landmass. Sand dunes, oases, hamadas or plateaus, and ergs, sand dunes with a high salt content, make up the desert. Just south of the Sahara lies the Sahel, a semi-arid band of land stretching from the west to east coast that acts as a transition zone between the desert and the more fertile land southward. To the east of the Sahel rises the Ethiopian highlands and to the south is the savanna.
The savanna or grasslands of Africa cover over five million square miles. To the west is the African rainforest, which covers much of the Congo and central Africa. The Swahili Coast lies on the eastern coast of Africa, boasting a variety of barrier islands and coral reefs. The southern region of Africa is made up of very old rock.