The Territory of Bioko, commonly known simply as Bioko, is an unincorporated territory of the Union of New Netherland located in Central Africa. Bioko includes two major islands (Annabon and Bioko) in the Gulf of Guinea, and a mainland territory (Rio Muni). New Netherland acquired the region from Spain in 1883 (becoming the only non-European nation to have a claim in Africa) and was organized into a territory in 1898.