When was the cite of carcassonne built?

The Cite of Carcassonne, a fortified city in France, has origins dating back to the Gallo-Roman period, with its construction beginning around the 1st century BC. The existing fortifications were significantly developed in the 12th century, particularly under the rule of the Viscounts of Carcassonne. The site is renowned for its double walls and numerous towers, which were further enhanced during the medieval period. Today, it is recognized as a UNESCO World Heritage site.