Fodor's Expert Review Château des Ducs de Bretagne

Built by the dukes of Brittany, who had no doubt that Nantes belonged in their domain, this moated 15th-century château looks well preserved, despite having lost an entire tower during a gunpowder explosion in 1800. François II, the duke responsible for building most of the massive structure, led a hedonistic life here, surrounded by ministers, chamberlains, and an army of servants. Numerous monarchs later stayed in the castle, where in 1598 Henri IV signed the famous Edict of Nantes advocating religious tolerance.