A tall round tower of rubble stone rises above the rock and the terraced walls on the slope below the castle. The fortress on the hill of Sévérac, probably fortified from the 9th century and remodelled in the 14th and 15th centuries, was protected by two lines of ramparts around the castle and a third around the town, and resisted most attacks except during the Albigensian Crusade, in 1214.