Kiambu County is a county of Kenya. It is located in the former Central Province, north of Nairobi, and its capital is Kiambu. The total population of the county is 1 623 282 inhabitants according to the 2009 census. The main northern peripheries of the Nairobi metropolitan area are in this county: here are the villages of Kikuyu and Karuri and the municipalities of Ruiru, Thika, Limuru and Kiambu. These six urban areas host two thirds of the county's population in the 2009 census.