Sagamu, city in southwestern Nigeria located in Ogun state near the Ibu River. The Sagamu region is underlain by major deposits of limestone, which is used in the city's major industry, the production of cement. Agricultural products of the region include cocoa and kola nuts. Sagamu is the largest kola nut collecting center in the country. The kola nut industry supports several secondary industries such as basket and rope manufacturing, which are used to store the kola nuts. Sagamu is the part of the Yoruba cultural region of southwestern Nigeria. The city was founded in the mid-1800s when several small towns united for purposes of defense. Sagamu controlled the trade routes between the ports in the Niger Delta and the Yoruba mainland until the British occupied the city at the end of the 19th century. Sagamu has experienced both population and economic growth since the 1950s due to its position between the cities of Ibadan and Lagos. Population (1995) 114,300.