The Roman aqueduct with a 1.5 cm slope

While it might have served the local town, some think the Aqueduct of Luynes was actually a private water line for a complex of villas at Sainte-Roselle. It was a sophisticated piece of engineering, constructed with a masonry channel that has a slope of 1.5 cm to 2.9 m per kilometre.

It stretched nearly two kilometres across the landscape, pulling water from the now-dry Pie Noire. The structure stayed in use for centuries, even surviving repairs in the 10th century under Charles the Simple. During those repairs, stones from collapsed piles were recovered and used, which is why it has survived so well despite the abandonment of the resort at Sainte-Roselle.

Today, you can see a stack of five arches standing in the Valley of the Arennes. It is one of the best-preserved northern aqueducts left. You can visit the ruins in Luynes to see the masonry construction that moved water across the valley to supply ancient Luynes, or even Caesarodunum.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons