Carcassonne

Ringed by nearly 3 kilometres of double walls and 52 towers, the Cité de Carcassonne is Europe's largest surviving medieval fortified town, its foundations Roman and its ramparts Visigothic and later. In 1209 it was besieged and captured during the Albigensian Crusade, the papal war against the Cathar heretics of southern France; its viscount, Raymond-Roger Trencavel, was imprisoned and died in its dungeon. Absorbed by the French crown, it guarded the frontier with Aragon until the border shifted in 1659, leaving it to decay. Slated for demolition in the 19th century, it was dramatically restored by architect Viollet-le-Duc from 1853, whose pointed turrets give it its fairy-tale silhouette.