Cairu is a municipality in the state of Bahia in the North-East region of Brazil. The municipality consists of three islands: the Island of Cairu, …Cairu is a municipality in the state of Bahia in the North-East region of Brazil. The municipality consists of three islands: the Island of Cairu, which is only separated from the mainland by a narrow river; Tinharé Island, which has the dense tourist settlement of Morro de São Paulo to the north; and Boipeba Island.