The large square at the western end of the old town is named for Bertrand du Guesclin, the 14th-century Breton knight whose equestrian statue dominates the space. Du Guesclin was one of the great military commanders of medieval France — rough, apparently ugly, tactically brilliant — and Dinan claims him as its own even though he was born at a castle some distance away.
The square hosts the Thursday morning market, which is one of the better reasons to time a visit to Dinan. Stalls sell Breton crêpes and galettes, cider and chouchen (Breton mead), oysters from the nearby coast, farmhouse cheeses, and seasonal vegetables. It's a proper working market rather than a tourist attraction, and the atmosphere reflects that.