The Château de Suscinio or de Susinio is a Breton castle, built in the late Middle Ages, to be the residence of the Dukes of Brittany. It is located in the commune of Sarzeau in the département of Morbihan, near the coast of the Atlantic ocean. The spectacular site comprises the moated castle, a ruined chapel, a dovecote, and a few ruined outbuildings. Designed to be a place of leisure, between the seaside and a forest full of game for hunting, the castle's first logis seigneurial dates from the beginning of the 13th century. The castle was fortified and enlarged, at the end of the 14th century, when the heirs of the duchy had to fight to keep their assets, after the castle was taken by Bertrand du Guesclin, the infamous Constable of France. John V and John VI constructed a new seigniorial residence block with a large, new corner tower known as the Tour Neuve. A casemate was added at the end of the 15th century to protect artillery pieces.