Avignon, France
It is a ruined bridge not far from the Palais des Papes. The bridge was built in the Middle Ages — before the arrival of the Papacy — perhaps partly to allow the local bishop to cross the river to Villeneuve-lès-Avignon, where the church authorities had installed themselves because of Avignon's then
-infamous dirt and lawlessness.
Listen to the audio guide for Pont Saint-Bénezet Free on WIP — starts by itself when you arrive, even with the screen off