The Cameroonian Highlands forests extend across the Cameroon Highlands, a chain of extinct volcanoes, covering an area of in eastern Nigeria and western Cameroon. The ecoregion lies above 900 meters elevation, and is surrounded at lower elevations by the Cross-Sanaga-Bioko coastal forests at the southern end of the range, and by Guinean forest-savanna mosaic along the central and northern ends of the range; the Cameroon Highlands form the boundary between the Guinean and Northern Congolian forest-savanna mosaic ecoregions. The highest mountain in the chain, Mount Cameroon is considered a separate ecoregion, while the highest peak within the region is Mount Oku (). As with similar highland areas in Angola and in East Africa the climate is cooler here than is typical of tropical Africa. The highlands are an important source of water for both Nigeria and Cameroon.