Castelo is a region in Rio de Janeiro, Brazil, but not officially recognized as a neighborhood, and officially forming part of the Centro neighborhood. It is generally considered to be located in the region between Rio Branco Avenue, the Santos Dumont Airport and Praça 15 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. As most of the buildings in the area were designed and built in the first half of the twentieth century, after the demolition of Morro do Castelo (Castle Hill) in 1921, the region became home to a large collection of Art Deco buildings. Art Deco was the prevalent architecture style in Rio de Janeiro at that time.