The last standing arch of Pont d'Ambrussum: a Roman staging post, medieval

Pont d'Ambrussum, also known as Pont Ambroix, is a 1st-century BC Roman bridge in France that was part of the Via Domitia, an ancient Roman road that ran from Italy to Spain. The bridge crossed the Vidourle river at Ambrussum between Gallargues-le-Montueux in the Gard department and Villetelle in the Hérault department. A chapel dedicated to St Mary was added to the structure in the High Middle Ages. Only one arch remains in the middle of the river.

The Colline de Devès, located just outside the village, was first occupied in 2300 BC and settled as an oppidum between 300 BC and 100 AD. Four arches of the bridge were reduced to three during the flood of 18 November 1745, and further floods on 6 October 1812, 21 October 1891, 21 September 1907, and 7 September 1933 reduced the bridge to the single arch we see today. The site was abandoned when transit patterns changed; the Via Domitia became less important and the community relocated to Lunel-Viel which better served a north–south transit pattern, but the bridge continued in use until the late Middle Ages.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons