The proposal was made by Iphan, the government agency in charge of historic and artistic patrimony.
It asks for official recognition of Rio’s landscape, with its singular combination of cultural and natural attractions.
Among the sites mentioned are the Sugarloaf mountain, the Christ the Redeemer statue, the botanical garden and Copacabana beach.
Unesco has recognised 18 cultural and natural sites in Brazil so far, including a national park in the Amazon, the historic city of Ouro Preto, and the capital, Brasilia.
Unesco is expected to make a decision in 2012.