Zanzibar (pron.: /ˈzænzɨbɑr/; from Arabic: زنجبار Zanjibār, from Persian: زنگبار Zangibār "Coast of Blacks"; zangi [black-skinned] + bār [coast]) is a semi-autonomous part of Tanzania, in East Africa. It is composed of the Zanzibar Archipelago in the Indian Ocean, 25–50 kilometres (16–31 mi) off the coast of the mainland, and consists of numerous small islands and two large ones: Unguja (the main island, referred to informally as Zanzibar), and Pemba.
Africa is the world's second-largest and second-most-populous continent. At about 30.2 million km² (11.7 million sq mi) including adjacent islands, it covers six percent of the Earth's total surface area and 20.4 percent of the total land area. With 1.0 billion people (as of 2009, see table), it accounts for about 15% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, both the Suez Canal and the Red Sea along the Sinai Peninsula to the northeast, the Indian Ocean to the southeast, and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagoes. It has 54 fully recognizedsovereign states ("countries"), 9 territories and two de facto independent states with limited or no recognition.
Africa, particularly central Eastern Africa, is widely accepted as the origin of humans and the Hominidaeclade (great apes), as evidenced by the discovery of the earliest hominids and their ancestors, as well as later ones that have been dated to around seven million years ago – including Sahelanthropus tchadensis, Australopithecus africanus, A. afarensis, Homo erectus, H. habilis and H. ergaster – with the earliest Homo sapiens (modern human) found in Ethiopia being dated to circa 200,000 years ago. Africa straddles the equator and encompasses numerous climate areas; it is the only continent to stretch from the northern temperate to southern temperate zones.