Castelo is a region in Rio de Janeiro, Brazil, but not officially recognized as a neighborhood, and officially forms part of the Centro neighborhood. It is generally considered to be located in the region between Avenida Rio Branco, the Santos Dumont Airport and Praça Quinze de Novembro. The area derives its name from the former Morro do Castelo in that location, which was demolished by water jets in the 1920s.