When you cross the bridge (once called the Ponte Elio) you have a splendid view of the Castle St Angelo. The bridge was built by Emperor Hadrian (130 AD), the Castle was his mausoleum.
The bridge is together with a double row of angels in the style of Bernini.
The Castle is worth a visit, a place rooted in legend and steeped in historymemories ofs bloodshed and crime. If you climb to the top (there is a cafe to rest tired feet) you'll be rewarded with breathtaking views over the city and St Peter's Basilica - definitely worth a visit.