The medieval fortified city of Carcassonne, located on a hill next to the Aude River on a strategic route between the Atlantic Ocean and Mediterranean Sea as well as the Iberian peninsula and the Massif Central, was already inhabited since the 6th century BC.
In the 1st century BC the Romans called it Colonia Iulia Carcaso. In the 3rd century the fortified walls were built, which are partly still existing today in the inner walls.
In the 13th century the outer walls were built, creating an almost invincible city. At the same time, the new city of La Bastide Saint-Louis was created on the other side of the Aude River.
The city walls and cathedral were restored in the second half of the 19th century by the architect Viollet-le-Duc.