Gallo-Roman Towers "les tours gallo-romaines": These towers are the oldest of the city. Their base or even the first level was usually filled in with masonry; the 2 others were used for defense. The towers were provided with a shutter swivelling on a horizontal central axis. This system allowed to protect oneself from aggressions and specially arrows right after having drawn some. The main characteristic of those towers consist in the masonry built with small stones and red brick chainings which were used to ensure a good cohesion for the stability.