Overview

The continent of Africa, the second largest on the globe, is bisected by the equator and bordered to the west by the Atlantic Ocean and to the east by the Indian Ocean. Roughly the shape of an inverted triangle—with a large bulge on its northwestern end and a small horn on its eastern tip—it contains 52 countries and six islands that, together, make up about 11.5 million square miles, or 20 percent of the world's land mass.

Africa is essentially a huge plateau divided naturally into two sections. Northern Africa, a culturally and historically Mediterranean region, includes the Sahara desert—the world's largest expanse of desert, coming close to the size of the United States. Sub-Saharan, or Black Africa, also contains some desert land, but is mainly tropical, with rain forests clustered around the equator; vast savanna grasslands covering more than 30 percent of continent and surrounding...