The door is a vestige of the urban surrounding wall(speaker) of the XIIIth century s., and had a double function(office) of bridge(deck) and of strengthened door. She(It) knew different allocations(appointments) and different periods of restoration(catering). At the end of the XIXth century s. in particular the building was transformed into medieval element, with all imaging appropriate(peculiar) to this period. This is the way(That's how) the crenellated facade of the building, often highlighted is due to the German architect Paul Tornow, which also intervened on the cathedral Saint-Etienne during the period of Annexation.

Villes et Pays d'art et d'histoire, Monument historique, Édifice militaire, enceinte urbaine