Guanabara Bay (Portuguese: Baía de Guanabara, IPA: [ɡwanaˈbaɾɐ]) is an oceanic bay located in Southeast Brazil in the state of Rio de Janeiro. On its western shore lies the city of Rio de Janeiro and Duque de Caxias, and on its eastern shore the cities of Niterói and São Gonçalo. Four other municipalities surround the bay's shores.