Dinan is a new French commune, created on January 1, 2018, resulting from the merger of the communes of Dinan and Léhon and a sub-prefecture located in the Côtes-d'Armor department in the Brittany region. It is a town in Poudouvre, a traditional country in the north of Upper Brittany.The town of Dinan is fortified by a belt of ramparts and was defended by an imposing castle. A strategic point for traffic between Normandy and the northern coast of Brittany, Dinan is built mainly on a hill.