Carcassonne

Carcassonne's inner wall is Roman and Visigothic, the outer one thirteenth-century, and by 1850 the whole thing was a slum scheduled for demolition until Viollet-le-Duc restored it — adding the conical slate roofs that scholars still argue about, since local towers were tiled and flat. Come at dusk when the coach parties have gone and the lit walls are visible from the new town below.