Castel Sant'Angelo

This Rome museum was created as a tomb for Emperor Hadrian and is an instantly recognizable monument. Based on an angelic vision that Pope Gregory the Great had in 590, it was later turned into a papal fortification in the sixth century. The mansion is now somber and dramatic, with a large collection of sculptures, paintings, medieval guns, and military artifacts. Weapons used by troops to guard the castle via the secret tunnel to the Vatican granted by the sanctuary to several of the popes in peril are among the military mementos.

The upper floor of the castle is packed with beautiful Renaissance interiors and the sumptuous Sala Paolina, which features murals representing scenes from Alexander the Great's life. Just two levels higher, the terrace gives a beautiful view of Rome, and Puccini immortalized it in his opera Tosca.

Location: Lungotevere Castello, 50, 00193 Roma RM, Italy

Website: castelsantangelo.com