An ancient Roman theater, the only surviving above-ground ruins of the Gallo-Roman era in Paris (ancient Lutetia, French Lutèce) apart from the nearby Thermes de Cluny. The theatre could hold approximately 15,000 spectators and measures some 132 m x 100 m. Built sometime in the 2nd century CE, the location of the actor's dressing room, the platform of the stage, and lapidary remains can still be seen. The remains were rediscovered in 1869, when new streets were being built. An excavation was subsequently ordered in 1883. The theatre has been preserved as a quiet archaeological park removed from the bustle of Parisian streets.

The Arènes de Lutèce are among the most important ancient Roman remains in Paris , together with the Thermes de Cluny. Constructed in the 1st century AD, this theatre could once seat 15,000 people and was used also as an amphitheatre to show gladiatorial combats. The terraced seating surrounded more than half of the arena's circumference, more typical of an ancient Greek theatre rather than a Roman one which was semi-circular. The orchestra was surrounded by the wall of a podium 2.5 m high, surmounted by a parapet. The stage was 41 m long. A series of nine niches were most likely used for statues. Five small rooms were situated beneath the lower terraces, some of which appear to have been animal cages that opened directly into the arena. One can still observe significant remnants of the stage and its nine niches, as well as the grilled cages in the wall. The stepped terraces are not original, but historians believe that 41 arched openings punctuated the façade.