Africa is the third biggest continent for its size followed by Asia and America, and the second most populated in the world. Its population represents 17% of the world population. Africa’s boundaries are: the Mediterranean Sea by the north; the Suez Canal and the Red Sea to the northeast, the Indian Ocean to the southeast and the Atlantic Ocean to the west. The largest island outside the mainland is Madagascar. It has 54 independent countries, Algeria is the more extensive, the most populated is Nigeria and the smallest is the Republic of the Seychelles. Africa has a great diversity of ethnicities, cultures and languages, human communities that have very ancient origins.Scientists recognize Africa as the cradleof humanity: it was there where hominids developed four million years ago.

The average height of Africa is 600 meters above sea level, and it does not have, like other continents, extremely high zones and other low ones, because plateaus predominate. Africa is a continent crossed by the equinoctial line and as it is so long, it extends from the temperate zones of the north to the temperate zones of the south, comprising numerous climatic zones.

• Sahara Desert:The warmestin the world, with 9 million km2 of elevation. It covers most of North Africa, from the Red Sea to the Atlantic Ocean.
  
  • Sahel:Tropical semi-arid savannah that borders to the north with the Sahara.
• Sudanese savanna:A tropical fruit savanna fringethat crosses the African continent, from the Atlantic Ocean to the Ethiopian massif.
• Forest of the Congo:After a transition zone from the Sahel, the Congo forest occupies most of the Africa center. The second largest tropical forest continues in the world after the Amazonia.
• Namib Desert:It is the oldest desert in the world, since it existed during the Tertiary Era, 65 million years ago.
  Kalahari Desert:Of 930,000 km2 of extension, it crosses several countries of the South African.
• Okavango Delta:More than a delta, because it does not go out to sea, it is an extensive alluvial region flooded by the Okavango River, it is born from a quite rainy area in Angola.
• Great Lakes:A high plateau along the Great Rift Valleys hosts a series of large lakes, the best known being Lake Victoria, the second largest freshwater lake in the world.
• Sierra of Kenya: A series of mountains including Mount Kenya, which is located in the center of the country to which it gives its name and is the second highest peak in Africa, after Kilimanjaro.
• Ethiopian Massif: It is the mountainous region, formed by high plateausand plateaus, which extends to an averageheight of 1,500 meters above sea level by Etopia, Eritrea and north of Somalia in northwest Africa.
• Great Rift Valley:It is a large geological fracture whose total extension is 4,830 km in a north-south direction, and in Africa it goes from Djibouti to Mozambique
  
  

Africa is irrigated by large rivers, although relatively few. The main ones are Nilo ( the second longest in the world), Congo (second the most aboundant in the world), Senegal, Volta, Niger-Benue, Orange, Limpopo and Zambezi.