This monument easily attracts viewers attention due to its shape and history, Castle S. Angelo. It is located not far from Via della Conciliazione, which is the main access to St. Peter's. Romans of the late Empire and Popes considered it always as a fortified castle, helping them to seek for safety during hard times. Its particular shape is because of its origin, when it was the great tomb of Emperor Adrian.

Adrian wanted to built a mausoleum for his family, it had to be similar to the one of Emperor Augustus, of course, it had to be much bigger and majestic. He also ordered the building of a new bridge to connect the two banks of the river, in those times only the other bank was largely populated. The name given to the new bridge was Elio. Today is known as Ponte Sant'Angelo and it gives you an outstanding view of St. Peter's, the river and the castle. Today, the fortress has been turned into a museum.

The legend of this building tells us that Pope Gregory I organized a procession because of the persistency of an epidemic. As the praying people marched in front of the mausoleum, the Pope himself saw St. Michael Angel with a sword of fire in his hand, the pestilence ended in that moment. In remembrance of that event, a statue of an angel with a sword was put on the tomb in the XIII century.