From the moat it is a defensive ring of granite towers and curtain wall. Step through the gate and the inside is an entirely different building: a late-Gothic palace in pale tuffeau limestone, with carved dormers and a loggia, built for living rather than for holding out.
The dukes of Brittany ran an effectively independent state from here until the duchy was absorbed into France; Anne of Brittany, twice queen of France, was born into this line and the building is where Brittany's separateness is most legible.
You can walk the ramparts and cross the courtyard without a ticket, which makes it one of the best free half-hours in the city. The museum inside — thirty-two rooms on the history of Nantes including the slave trade — is the ticketed part.
Walk the rampart walk at the end of the day. It is free, it circles the whole castle, and it is the clearest view you will get of how the old town is laid out.
Château des Ducs de Bretagne in pictures
