Nairobi (/naɪˈroʊbi/) is the capital and the largest city of Kenya. The name comes from the Maasai phrase Enkare Nairobi, which translates to "cool water", a reference to the Nairobi River which flows through the city. The city proper had a population of 3,138,369 in the 2009 census, while the metropolitan area has a population of 6,547,547. The city is popularly referred to as the Green City in the Sun.[3]

With a population of 3.36million in 2011, Nairobi is the second-largest city by population in the African Great Lakes region after Dar es Salaam, Tanzania.[1][8] According to the 2009 census, in the administrative area of Nairobi, 3,138,295 inhabitants lived within 696km2 (269sqmi).[9] Nairobi is the 10th-largest city in Africa, including the population of its suburbs.