It’s a bridge (Pont Barré) over the river Layon, built in XI century, restored in 1988.
The river Layon, was sort of a frontier between the region Anjou and Poitou. The bridge Barré was a demarcation point between Republicans and Royalists during the Vendée War (1793).
As at those days, the tax of salt was higher in Anjou then in Poitou. there were farm soldiers on the bridge controlled the traffic of salt between these two regions.
There are vineyards around the valley Layon, a very good white vin Coteau de Layon is from here.