Built as a fortress from the outset in the 16th C. the Rocca Pia in Tivoli has constantly been refurbished by long-standing Roman nobility right up to its current configuration, .

The building has a square plan. Circular towers with Guelph embattlements stand at the four corners, connected by walls with walkways, which go to form a square internal yard.

An overall view of the monumental complex of Rocca Pia gives one an immediate idea of the resolve behind the papal commission and the magnificence of the architecture. Once the extensive restoration work was completed, the Province of Rome handed it over to the Tivoli Council that now uses it as an exhibition space.