It officially became Nigeria's capital on 12 December 1991, replacing Lagos, though the latter remains the country's most populous city. 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.
Abuja has witnessed a huge influx of people into the city; the growth has led to the emergence of satellite towns such as Karu Urban Area, Suleja, Gwagwalada, Lugbe, Kuje and smaller settlements to which the planned city is sprawling. The unofficial metropolitan area of Abuja has a population of well over three million and comprises the fourth largest urban area in Nigeria, surpassed only by Lagos, Kano and Ibadan.
Abuja's geography is defined by Aso Rock, a 400-metre monolith left by water erosion. The Presidential Complex, National Assembly, Supreme Court and much of the town extend to the south of the rock. Zuma Rock, a 792-metre monolith, lies just north of the city on the road to Kaduna.
Significant sights include the Nigerian National Mosque and the Nigerian National Christian Centre. The city is served by the Nnamdi Azikiwe International Airport. Abuja is known for being one of the few purpose-built capital cities in Africa as well as being one of the wealthiest and most expensive. However, some people living on the edges of the city live in semi-developed rural areas such as Nyanya and Durumi.
Abuja's Central District, also called Central Area, spans from the foot of Aso Rock, across the Three Arms Zone, to the southern base of the inner ring road. It is like the city's spinal cord, dividing it into the northern sector with Maitama and Wuse, and the southern sector with Garki and Asokoro.
While each district has its own clearly demarcated commercial and residential sectors, the Central District is the city's principal Business Zone, where practically all parastatals and multinational corporations have their offices.
An attractive area in the Central District is the region known as the Three Arms Zone, so called because it houses the administrative offices of the executive, legislative and judicial arms of the federal government.
A few of the other sites worth seeing in the area are the federal secretariats alongside Shehu Shagari Way, Aso Hill, the Abuja Plant Nursery, Eagle Square (which has important historic significance, as it was in this grounds that the present democratic dispensation had its origin on 29 May 1999) and the Tomb of the Unknown Soldier across the road facing it.
The National Mosque and National Church of Nigeria are opposite each other on either side of Independence Avenue. A well-known government office is the Ministry of Defense, colloquially nicknamed "Ship House".
The Garki District is the area in the southwest corner of the city, having the Central District to the north and the Asokoro District to the east. The district is subdivided into units called "Areas". Garki uses a distinctive naming convention of "Area" to refer to parts of Garki. These are designated as Areas 1 to 11. Garki II is used to differentiate the area from Garki Area 2. Visitors may find this system confusing.
Garki is presently the principal business district of Abuja. Numerous buildings of interest are in this area. Some of them include the General Post Office, Abuja International Conference Centre along the busy Herbert Maculay Way, Nicon Luxury Hotel (formally known as Abuja Sofitel Hotel and Le Meridian), Agura Hotel and Old Federal Secretariat Complex Buildings (Area 1). A new five-star hotel, Hawthorn Suites Abuja, is in Garki.
Area 2 is mainly used for residential purposes, although a zoological garden as well as Garki Shopping Centre are in Area 2. Several banks and other commercial offices are located along Moshood Abiola Way in Area 7. The headquarters of the Nigerian Armed Forces – Army, Airforce and Navy – are all in the Garki District.
The tallest building in this district is the Radio House, which houses the Federal Ministry of Information and Communications, and the Federal Radio Corporation of Nigeria (FRCN). The Nigerian Television Authority (NTA) stations and corporate headquarters are based in Garki. The Federal Capital Development Authority (FCDA) which oversees and runs the Administration of the Federal Capital Territory has its offices in Garki.
The Office of the Minister of the Federal Capital Territory, Abuja is in Area 10. Other places of note include the Arts and Culture Centre and The Nigerian Police Mobile Force headquarters in Area 10. The Abuja Municipal Area Council, which is the local government administration has its headquarters in Area 10. The new United States Embassy is in the Garki district.
Wuse District is the northwestern part of the city, with the Maitama District to its north and the Central District to its south. The District is numbered Zones 1–8. The Wuse Market is Abuja's principal market (Zone 5). The second most important post office in the city is here.
This district houses the Sheraton Hotel and Towers (Zone 4), Ibro International hotel, the Foreign Affairs Ministry Headquarters (Zone 3) and Nigerian Customs Services Headquarters, Federal Civil Service Commission (Zone 3), Federal Road Safety Commission (FRSC), National Agency for Food and Drugs Administration (NAFDAC) (Zone 7), Wuse General Hospital, and the Nigerian Tourism Development Corporation. Just as Garki District has Garki II, Wuse has Wuse II. This is distinct from Wuse Zone 2.
Maitama District is to the north of the city, with the Wuse and Central Districts lying to its southwest and southeast respectively. This area is home to the top bracket sections of society and business, and has the reputation of being very exclusive and very expensive.
Interesting buildings include the Transcorp Hilton Hotel, Nigerian Communications Commission Headquarters (NCC), National Universities Commission (NUC), Soil Conservation Complex, and Independent National Electoral Commission (INEC).
The British High Commission is located along Aguiyi Ironsi Way, in Maitama. Also, the Maitama District Hospital is another notable building in Maitama. Maitama District is home to many of the European embassies.
Asokoro District, the doyen of the districts, houses all of the state's lodges/guest houses. The ECOWAS secretariat is a focal point of interest. Asokoro is to the east of Garki district and south of Central district. It is one of the most exclusive districts of Abuja and houses virtually all of the federal cabinet ministers; in addition, the Presidential Palace (commonly referred to as the Aso Rock) is in Asokoro district. By virtue of this fact, Asokoro is the most secure area of the city.
Gwarimpa is the last district in the Abuja Municipal Area Council. It is a 20-kilometer drive from the central district and contains the largest single housing estate in Nigeria, the Gwarimpa Housing Estate. The estate was built by the administration of General Sani Abacha and is the largest of its kind in Africa.
It provides residence for the majority of the civil servants in federal ministries and government parastatals. The ECOWAS Court has an official quarters for the President and Members of the Court in Gwarimpa.
Durumi District is located southwest of Abuja and is bordered by Garki Districts I and II to the northeast. Its borders are the Oladipo Dia Road to the southwest, the Nnamdi Azikiwe Express Way to the northeast, and Ahmadu Bello Way to the southeast.
The American International School of Abuja is located in the Durumi District.