Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa and the most populous country on the African continent. Nigeria shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, Niger in the north, and borders the Gulf of Guinea in the south. Since 1991, its capital has been the centrally-located city of Abuja; previously, the Nigerian government was headquartered in Lagos.

The people of Nigeria have an extensive history, and based on archaeological evidence, human habitation of the area dates back to at least 9000 BC. The Benue-Cross River area is thought to be the original homeland of the Bantu migrants who spread across most of central and southern Africa in waves between the 1st millennium BC and the 2nd millennium AD. However, the Nigerian state came into being on October 1, 1960 when Nigeria declared its independence from the British and at present consists of 36 states and the federal capital territory. Nigeria re-achieved democracy in 1999 after a sixteen-year interruption by a series of military dictators.

From 1966 until 1999, Nigeria had been ruled (except the short-lived second republic, 1979-1983) by military dictators who seized power in coups and counter-coups.

Located in western Africa on the Gulf of Guinea, Nigeria has a total area of 356,669 mi² (923,768 km²[1]); of that around 5,000 square miles (13,100 km²) is water. Its size makes it the world's 32nd-largest country (after Tanzania). It is comparable in size to Venezuela, and is a little more than half the size of the US state of Alaska. It shares a 2,515-mile (4,047-km) border with Benin, Cameroon, Chad and Niger.

The highest point in Nigeria is Chappal Waddi at 7,936 feet (2,419 m).

Nigeria has a varied landscape. From the Obudu Hills in the southeast through the beaches in the south, the rainforest, the Lagos estuary and savanna in the middle and southwest of the country and the Sahel and the encroaching Sahara Desert in the extreme north.

Nigeria's main rivers are the Niger, the Benue which converge and empty out in the Niger Delta, one of the world's largest river deltas. Nigeria is also an important centre for biodiversity. It is widely believed that the areas surrounding Calabar, Cross River State contain the world's largest diversity of butterflies. The drill monkey is only found in the wild in Southeast Nigeria and neighbouring Cameroon.