Niteroi is a municipality in the state of Rio de Janeiro, southeast region of Brazil. Integrates the Metropolitan Region of Rio de Janeiro. The city has the nicknames of Niquiti and the Smile City. Studies by the Getulio Vargas Foundation in June 2011 classified Niteroi as the richest city of Brazil, owning 30.7% of the population included in class A. The word "Niteroi" comes from the Tupi language and means water that hides. It makes Niteroi the only Brazilian city to have been founded by a non-Christian, non-assimilated Brazilian Amerindian.