The Old Cathedral of Rio de Janeiro dedicated to Our Lady of Mount Carmel (full name in Portuguese: Igreja de Nossa Senhora do Monte do Carmo da antiga Sé, lit. 'Church of Our Lady of Mount Carmel of the Ancient See') is an old Carmelite church which served as cathedral (Sé) of Rio de Janeiro from around 1808 until 1976. During the 19th century, it was also used successively as Royal and Imperial Chapel by the Portuguese Royal Family and the Brazilian Imperial Family, respectively. It is located in the Praça XV square, in downtown Rio. It is one of the most important historical buildings in the city.