Corn Island is a municipality in the Región Autónoma del Atlántico Surdepartment of Nicaragua. A municipality or general-purpose district (compare with: special-purpose district) is an administrative local area generally composed of a clearly defined territory and commonly referring to a city, town, or village government. ... Región Autónoma del Atlántico Sur, sometimes shortened to RAAS, is an autonomous region in Nicaragua. ... Nicaragua is a unitary republic. ...