Glanum Dam (1891)

The Glanum Dam, also known as the Vallon de Baume dam, was a Roman arch dam built to supply water to the Roman town of Glanum, the remains of which stand outside the town of Saint-Rémy-de-Provence in southern France. It was situated south of Glanum, in a gorge that cut into the hills of Les Alpilles in the Roman province of Gallia Narbonensis. Dating to the 1st century BC, it was the earliest known dam of its kind.

Source: Wikipedia