Ponte Rotto (Pons Aemilius)

A single melancholy stone arch in the middle of the Tiber — all that remains of Rome's first stone bridge, originally built in the 2nd century BC. It was repeatedly damaged by floods due to the river's turbulent current at this bend, and despite multiple reconstructions it was finally abandoned in 1598. Most of the structure was demolished in the 19th century to improve river navigation. Best photographed at sunset from the modern Ponte Palatino just upstream.