Loire-Atlantique is the department that marks the end of the Loire Valley as it reaches the Atlantic, where the royal river widens into a vast estuary before flowing into the ocean. Nantes, the former capital of the Duchy of Brittany and an Atlantic metropolis, is the historical and cultural heart of the department, with the Château des Ducs de Bretagne as its most iconic monument.
The Château des Ducs de Bretagne, a medieval fortress with crenellated curtain walls contrasting with the Renaissance palace within it, was the residence of the Dukes of Brittany and later the seat of the royal governor following its annexation to France in 1532. It now houses the Nantes History Museum and bears witness to five centuries of regional history. Clisson Castle, the romantic ruins of a medieval fortress set within an Italianate garden designed by the Cacault and Lemot brothers in the 19th century, is another remarkable site.
Loire-Atlantique also boasts numerous manor houses in the Muscadet vineyards, châteaux in the Pays de Retz and neo-Gothic residences along the Côte de Jade coastline, which bear witness to the bourgeois prosperity of the 19th century in this department of trade and shipping.