What about the Castel Sant’Angelo in Rome ?

Castel Sant'Angelo, also known as the Mysterious Fortress, is a medieval Catholic Church located in Rome, Italy. It was built to enshrine the bodies of the early popes and is Rome's oldest religious building. Castel Sant'Angelo was also used to imprison Christians before they were thrown into the infamous Vatican prison cells. It was built during the 1st century on the orders of the Emperor Hadrian on the site of an earlier pagan temple.

The story around this building

The fortress is named after the angel Saint Angelo and was built to defend the city against invaders. To learn more, check my source. Emperor Theodosius II ordered construction to be halted in 401, but Pope Leo III picked up where he left off and completed construction under his direction. He also added a protective wall and a moat. However, there are claims that contemporaries viewed this project as something of a 'waste of time.' In addition, contemporary critics accused Leo of misusing funds to construct this unnecessary monument, which he defended by claiming it was divinely inspired.

A monument that keeps talking about itself

Castel Sant'Angelo is an ancient religious monument that has witnessed many historical events surrounding the papacy over the past 1,000 years. It is currently managed by the Vatican Secretariat of State and serves as a military museum representing Mussolini's fascist regime. Castel Sant'Angelo was the most important structure in the Roman Catholic Church for over nine hundred years. The popes who lived in the palace used it as a residence for several centuries. 

However, the papal apartments were not used as much as they were originally constructed for; instead, they served as a storage area for church artifacts. The popes never considered Castel Sant'Angelo their home because it was too large and drafty. Furthermore, many popes found it inconvenient to live so close to their work spot, while others found living there too confining and chose instead to reside at the Vatican Palace.