In the center of the Château de Gruissan in the Aude department, the prison tower offered an ideal observation post. Its unique exit allowed easy control of the prisoners, making any escape almost impossible. Located on the rock emerging from the Aude delta, the tower stands as a vigilant sentinel on the navigation of the Narbonne port. The fortress was demolished in 1632 by order of King Louis XIII and later transformed into a quarry. The stones were first reused for the construction of the Saint-Just cathedral in Narbonne and then, 30 years later, for the parish church at the foot of the rock of Gruissan.