Looking across the River Tiber towards the Castel Sant'Angelo and its bridge, after sunset on a clear summer's evening in the heart of Rome. The Castel Sant'Angelo began life as a mausoleum commissioned by the Roman Emperor Hadrian for himself and his family in the 2nd century, and was later used by the popes as a fortress and place of refuge. The bridge also dates to Hadrian's time, with various changes and additions over the centuries – most notably, the series of angel statues by Gian Lorenzo Bernini, in the late 1660s.