Cité de Carcassonne

Few old towns anywhere give you walls on this scale: about 3 km of double ramparts punctuated by 52 towers, wrapped around a hilltop cité you can walk end to end in an hour. Go knowing what you are seeing. The restoration that began in 1853 under Eugène Viollet-le-Duc saved the place from decay but also reimagined it, and his pointed slate roofs on the towers have been criticized since his own lifetime as wrong for the region. Treat it as a medieval fortress seen through nineteenth-century eyes. Arrive early or stay for the evening, when the day visitors leave and the lanes inside the walls empty out.