Rio de Janeiro , 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, boasting approximately 6.3 million people within the city proper, making it the 6th largest in the Americas, and 26th in the world. Rio de Janeiro has become a home of a World Heritage Site named "Rio de Janeiro: Carioca Landscapes between the Mountain and the Sea", as granted by UNESCO on 1 July 2012 in the category Cultural Landscape.