Niterói (Portuguese pronunciation: [niteˈɾɔj], [nitɛˈɾɔj]) is a municipality of 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 forms part of the Rio de Janeiro Metropolitan Area. It was the state capital, as marked by its golden mural crown, between 1834~1894 and again between 1903~1975. It has an estimated population of 487,327 inhabitants (2010) and an area of 129.375 km (80.39 mi), making it the sixth most populous city in the state. It has the highest Human Development Index of the state. The city has the nicknames of Nikity, Nicki City and the Smile City (Cidade Sorriso).