Ponte Sant'Angelo, Rome

Hadrian's bridge over the Tiber at dusk, with the dome of St. Peter's rising behind it. Completed in AD 134 as the Pons Aelius, it led to the emperor's mausoleum, now Castel Sant'Angelo. Three of its five arches are Roman. The two at the ends replaced the old ramps in the late 19th century, when the Tiber embankments were built, and they were made to match. The marble angels along the parapets came from a program Pope Clement IX gave Bernini in 1669; the two angels Bernini carved himself were kept indoors and now stand in the church of Sant'Andrea delle Fratte, so the bridge carries copies of those. It is now a pedestrian crossing.