Museo di Castel Sant'Angelo

Rising above the river, Hadrian designed his massive circular tomb in 123-139AD. Aurelian fortified it in 271 as part of his city walls. It was the papal castle for 1000 years - a viaduct from the Vatican let the popes scurry here in times of crisis. Gregory the Great named it in 590 after a vision of St. Michael announced the end of a plague from its tower, marked by the bronze statue of a sword - bearing archangel. There are frescoed Renaissance papal apartments and a small arms and armour collection, plus stunning panoramas of the city from the ramparts.