<Tr> <Th> Climate </Th> <Td> Aw </Td> </Tr> <Tr> <Th> Website </Th> <Td> www.fcta.gov.ng </Td> </Tr> <P> Abuja (/ əˈbuːdʒə /) is the capital city of Nigeria located in the centre of the country within the Federal Capital Territory (FCT). It is a planned city and was built mainly in the 1980s, replacing the country's most populous city of Lagos as the capital on 12 December 1991 . Abuja's geography is defined by Aso Rock, a 400 - metre (1,300 ft) monolith left by water erosion . The Presidential Complex, National Assembly, Supreme Court and much of the city extend to the south of the rock . Zuma Rock, a 792 - metre (2,598 ft) monolith, lies just north of the city on the expressway to Kaduna . </P> <P> At the 2006 census, the city of Abuja had a population of 776,298, making it one of the ten most populous cities in Nigeria . According to the United Nations, Abuja grew by 139.7% between 2000 and 2010, making it the fastest growing city in the world . As of 2015, the city is experiencing an annual growth of at least 35%, retaining its position as the fastest - growing city on the African continent and one of the fastest - growing in the world . As at 2016, the metropolitan area of Abuja is estimated at six million persons, placing it behind only Lagos, as the most populous metro area in Nigeria . </P>

When was abuja became the capital of nigeria