Carcassonne (kärkäsônˈ) [key], city (1990 pop. 44,911), capital of Aude dept., S France, in Languedoc. The old city, a medieval fortress atop a hill, is one of the architectural marvels of Europe. The new city, across the Aude River, is a farm trade center with rubber, shoe, and textile manufactures. Tourism, however, is the main industry. The Romans fortified the hilltop site in the 1st cent. B.C.; towers built (c.6th cent.) by the Visigoths are still intact; and the viscounts of Carcassonne added to the fortifications in the 12th cent. A stronghold of the Albigenses, the fortress was taken by Simon de Montfort in 1209. It yielded to the king in 1247, at which time Louis IX (St. Louis) founded the new city across the river. The outer ramparts of the fortress were constructed during St. Louis's reign, and the work was continued, with intricate defense devices, under Philip III. When completed, the fortress was widely considered impregnable; Edward the Black Prince was stopped at its walls in 1355. However, its usefulness ended in 1659, with the annexation to France of the province of Roussillon. The ramparts were gradually abandoned and fell into disrepair; they were restored by Viollet-le-Duc in the 19th cent.