The Benedictine abbey of Saint-Florent, founded in the 9th century, stood for almost a thousand years on the western edge of Saumur and at one point owned much of the surrounding countryside. The French Revolution closed the monastery and most of the buildings were sold off and dismantled in the 19th century.
What remains is a fragmentary but evocative ruin — sections of cloister wall, a 17th-century gateway, and the parish church of Saint-Pierre, which incorporates earlier abbey stonework. The site is open and free to wander; signage explains the history. Worth combining with a walk along the western waterfront.