Africa, second largest of Earth’s seven continents, covering 23 percent of the world’s total land area and containing 13 percent of the world’s population. Africa straddles the equator and most of its area lies within the tropics. It is bounded by the Atlantic Ocean on the west, the Indian Ocean and Red Sea on the east, and the Mediterranean Sea on the north. In the northeastern corner of the continent, Africa is connected with Asia by the Sinai Peninsula.

Africa is a land of great diversity. If you were to trek across the continent, you would pass through lush, green forests and wander vast, grassy plains. You would cross barren deserts, climb tall mountains, and ford some of the mightiest rivers on Earth. You would meet diverse people with a wide range of cultures and backgrounds and hear hundreds of different languages. You would pass through small villages where daily life remains largely the same as it has been for hundreds of years, as well as sprawling cities with skyscrapers, modern economies, and a mix of international cultural influences.

Africa is the birthplace of the human race. Here, early humans evolved from apes between 8 million and 5 million years ago. Modern human beings evolved between 130,000 and 90,000 years ago, and subsequently spread out of Africa. Ancient Egypt, one of the world’s first great civilizations, arose in northeastern Africa more than 5,000 years ago. Over time many other cultures and states rose and fell in Africa, and by 500 years ago there were prosperous cities, markets, and centers of learning scattered across the continent.

During the last 500 years, Africa became increasingly dominated by European traders and colonizers. European traders sent millions of Africans to work as slaves on colonial plantations in North America, South America, and the Caribbean. Europeans also sought Africa’s wealth of raw materials to fuel their industries. In the late 19th century, European powers seized and colonized virtually all of Africa.

Through slow reform or violent struggle, most of Africa won independence in the 1950s and 1960s. Independent Africa inherited from colonization a weak position in the global economy, underdeveloped communication and transportation systems, and arbitrarily drawn national boundaries. The citizens of these new nations generally had little in terms of history or culture to bind them together.

There are 53 different African countries, including the 47 nations of the mainland and the 6 surrounding island nations. The continent is commonly divided along the lines of the Sahara, the world’s largest desert, which cuts a huge swath through the northern half of the continent. The countries north of the Sahara make up the region of North Africa, while the region south of the desert is known as sub-Saharan Africa. Sub-Saharan Africa is sometimes referred to as “Black Africa,” but this designation is not very helpful, given the ethnic diversity of the entire continent.

The African continent covers 30 million sq km (12 million sq mi), including its adjacent islands. It stretches 8,000 km (5,000 mi) from its northernmost point, Ra’s al Abyaḑ in Tunisia, to its southernmost tip, Cape Agulhas in South Africa. The maximum width of the continent, measured from the tip of Cap Vert in Senegal, in the west, to Raas Xaafuun (Ras Hafun) in Somalia, in the east, is 7,500 km (4,700 mi). The highest point on the continent is the perpetually snowcapped Kilimanjaro (5,895 m/19,341 ft) in Tanzania, and the lowest is Lake ‘Asal (153 m/502 ft below sea level) in Djibouti.

Africa is surrounded by oceans and seas: the Atlantic Ocean on the west, the Indian Ocean on the east, the Red Sea on the northeast, and the Mediterranean Sea on the north. Madagascar, the fourth largest island in the world, lies off the southeastern coast. Other offshore islands include the Madeira Islands, Canary Islands, Cape Verde Islands, São Tomé, Príncipe, and Bioko, off the western coast; and the Comoros Islands, Seychelles, Mascarene Islands, and Socotra, off the eastern coast.

Africa generally consists of a series of flat and gently undulating plateaus occurring at different levels, broken by a few mountainous areas and by the rift valleys of East Africa. With a mean elevation of approximately 650 m (2,100 ft) above sea level, Africa is high compared to other continents. The southern and eastern section of the continent, often called High Africa, consists primarily of a high plateau with elevations between 1,000 and 2,000 m (3,000 and 7,000 ft) above sea level.

Northern and western Africa, widely known as Low Africa, has much lower mean elevations. Most of the continent’s surface has been warped into a series of large, saucer-like basins separated by highlands. The major basins of Africa are El Djouf, now occupied by the Niger River Basin in West Africa; the Chad Basin, surrounding Lake Chad in west central Africa; the Sudan (or Nile River) Basin in northeast Africa; the Congo River Basin of Central Africa; and the Kalahari (or Okavango) Basin of southern Africa.

Scientists use the theory of plate tectonics to explain the formation of Africa and the other continents. According to this theory, the crust of Earth’s surface consists of a collection of 14 rigid plates floating on an underlying mantle. These plates are in constant motion—moving apart, colliding, and thrusting beneath one another. Africa sits at the center of the African Plate, one of the largest of Earth’s plates.

For much of Earth’s history, the land made up one vast supercontinent known as Pangaea. About 220 million years ago, tectonic activity broke Pangaea apart into the supercontinents of Gondwanaland and Laurasia. Gondwanaland subsequently broke apart as well: First Antarctica, Australia, Madagascar, and the Indian subcontinent broke away, followed by South America. Africa, at the core of Gondwanaland, assumed roughly its present-day shape about 15 million years ago when the formation of the Red Sea split off the Arabian Peninsula.