Osun State

Osun (/ˈoʊʃuːn/ OH-shoon; Yoruba: Ìpínlẹ̀ Ọ̀ṣun [ìk͡pĩ́lɛ̀ ɔ̀ʃũ̄] ), is a state in southwestern Nigeria; bounded to the east by Ekiti and Ondo states for 84 km and for 78 km respectively, to the north by Kwara State for 73 km, to the south by Ogun State for 84 km and to the west by Oyo State, mostly across the River Osun. Named after the River Osun—a vital river which flows through the state—the state was formed from the southeast of Oyo State on 27 August 1991 and has its capital as the city of Osogbo.

Of the 36 states of Nigeria, Osun is the ninth smallest in area and 25th most populous state with an estimated population of about 4.7 million as of 2016. Geographically, the state is divided between the Nigerian lowland forests in most of the state and the drier Guinean forest–savanna mosaic in the north. The major geographical features are rivers including the state's namesake, the River Osun which bisects the state's interior before forming much of the state's southwestern border with Oyo State and flowing south. Other important rivers are the Erinle and Oba rivers, both Osun tributaries which flow from the north before meeting the Osun along the southwestern border. Among the state's fauna are mona monkey, common kestrel, purple heron, and royal antelope, along with some of Nigeria's last remaining Nigeria-Cameroon chimpanzee and African forest elephant which inhabit the heavily threatened forests along the southern borders with Ondo and Ogun states.