Av. Joao Luis Alves Urca, Rio de Janeiro - RJ, 22291-090, Brazil
Fortaleza de Sao Joao da Barra do Rio de Janeiro,popularly known to the
Fortress of St. John or
Fort (of) St.John (Fort of St. John), is a 16th-century star fort in the present-day Urca neighborhood of Rio de Janeiro,erected by Estacio de Sa to protect Guanabara Bay from French invasion .