St Angel's Bridge is a five-span construction in the centre of Rome, next to St Angel's Castle. The castle is in fact a mausoleum built by emperor Hadrian for his family on the bank of the Tiber River, opposite the Campus Martius. In order to make access to the building easier, in 2nd century A.D. the bridge was built, which was called the Elius Bridge. Its name - as well as the name of the mausoleum - was changed by pope Gregory I. At present the bridge and the castle are great tourist attractions of that part of Rome.