Talk Group of the City of Niterói RJ Brazil. Niterói, affectionately nicknamed "Cidade Sorriso" (City of Smiles), is a vibrant municipality located in the metropolitan region of the state of Rio de Janeiro, separated from the capital by Guanabara Bay. With over 500,000 inhabitants, the city combines a rich colonial history, an important urban center, and paradisiacal beaches. Niterói is the only Brazilian city founded by an indigenous person, Arariboia, chief of the Temiminó tribe, in 1573. Its name in Tupi means "Hidden Waters". For a long period (until 1975), it was the capital of the state of Rio de Janeiro.