The first defences for the walled town of Segovia were probably built in the Roman era. The current walls and Alcazar (fortress) are medieval. The Alcazar has since been used as a palace and a prison, but is now open to tourists. The walls fell into decline but more recently attempts have been made to preserve them and you can still walk along some parts of the walls. Together with the historic old town of Segovia, the walls and Alcazar became a UNESCO World Heritage Site in 1985.
The Château Comtal (Count’s Castle) is a medieval castle within the Cité of Carcassonne, the largest city in Europe with its city walls still intact. The Château Comtal has a strong claim to be called a 'Cathar Castle'. When the Catholic Crusader army arrived in 1209 they first attacked Raymond-Roger Trencavel's castrum at Bèziers and then moved on to his main stronghold at Carcassonne.
The castle with rectangular shape is separated from the city by a deep ditch and defended by two barbicans. There are six towers curtain walls.
The castle was restored in 1853 by the architect Eugène Viollet-le-Duc. It was added to the UNESCO list of World Heritage Sites in 1997.