Niterói is a municipality in the state of Rio de Janeiro, in the southeast region of Brazil. It lies across Guanabara Bay, facing the city of Rio de Janeiro and forming part of the Rio de Janeiro Metropolitan Area. It was the capital of Rio de Janeiro, as marked by its golden mural crown, from 1834 to 1894 and again from 1903 to 1975. It has an estimated population of 515,317 inhabitants and an area of 129.375 km2, making it the fifth most populous city in the state.