Know the castle and the ramparts of the city of Carcassonne. A key city in the formation of the national territory. Center of the power of the counts of Carcassonne then of the famous Trencavel family in the 12th century, it became, following the Albigensian crusade (1209-1229) where the royal forces seized Carcassonne, accused of complicity with the Cathars, a place royal stronghold governed by a seneschal.