Castle of the Holy Angel

Originally constructed as the imperial mausoleum for Emperor Hadrian in 139 AD, this structure has served multiple functions including a fortress, papal residence, and prison. It is a quadrangular building that combines elements of a mausoleum with military fortifications. The site is now a museum showcasing these varied historical roles along with architectural developments over the centuries.

The fortress also includes a notable papal escape route known as the Passetto di Borgo, emphasizing its strategic importance during papal times. Panoramic views of the surrounding city are available from the upper levels, highlighting its position as both a defensive structure and a place of prominence.

The museum offers immersive multimedia experiences and exhibits that illustrate its transformation from mausoleum to fortress and prison, reflecting the layered history of Rome. The site is wheelchair accessible and included in cultural passes such as the Omnia Vatican and Rome Card.