The Orange arc, set up in the north of the city to approximately 70 meters in the north of the ramparts, is a rather massive building with three bays whose decoration evokes the absolute power of Rome. On its faces north and south, Celtic weapons of the period of independence appear as hung in range on a wall; on its sides east and west, the Celts are represented connected. Weapons and prisoners seem eternal trophies carved in the stone pointing out the permanence of the domination that triumphing Rome exerts on the people of the area. To this decoration that of naval skins is added where prows, oars, anchors and aplustres, under the benevolent eye of sirens and marine monsters, mix in an erudite disorder, recalling the control on the maritime world that the victory of Actium gave in Rome. Lastly, on the higher attic, in a narrow fray, clash riding and infantrymen, pointing out the old topic pergaménien which oppose Greek and Galates which, here, became Romans and Celts.
The Orange theatre owes its reputation with its exceptional conservation. It presents all the components of the Latin theatre according to Vitruve: the cavea (steps in hemicycle), accesses side and the wall of scene flanked of parascaenia. Conceived to accomodate the Gallo-Roman public, it is by this place which the diffusion of the culture and the Roman language passed.
9000 spectators could attend tragedies, comedies but also with spectacles of dance, acrobatics and juggling.
Forgotten in IVème century, it is transformed thereafter into district of dwelling.