Rio de Janeiro ("River of January", English pronunciation: /ˈriːoʊ deɪ dʒəˈnɛəroʊ/; local Portuguese pronunciation: [ˌxiudʒiʒaˈnejɾu]), commonly referred to simply as Rio, is the capital city of the State of Rio de Janeiro, the second largest city of Brazil and the third largest metropolitan area and agglomeration in South America, 6th largest in the Americas and 26th in the world.
The city was the capital of Brazil for nearly two centuries, from 1763 to 1815 during the Portuguese colonial era, 1815 to 1821 as the capital of the United Kingdom of Portugal, Brazil and Algarves, and from 1822 to 1960 as an independent nation. Rio is nicknamed the Cidade Maravilhosa or "Marvelous City."
Rio de Janeiro represents the second largest GDP in the country  (and 30th largest in the world ), estimated at about 140 billion reais (IBGE/2007), and is the headquarters of two major Brazilian companies – Petrobras and Vale, and major oil companies and telephony in Brazil, besides the largest conglomerate of media and communications companies in Latin America, the Globo Organizations. The home of many universities and institutes, it is the second largest center of research and development in Brazil, accounting for 17% of national scientific production – according to 2005 data.