The Arènes de Lutèce are among the most important remains from the Gallo-Roman era in Paris (formerly known as Lutèce in French or Lutetia in Latin), together with the Thermes de Cluny. Lying in what is now the Quartier Latin, this amphitheater could once seat 15,000 people, and was used to present gladiatorial combats.
Constructed in the 1st century AD, this amphitheater is considered the longest of its kind constructed by the Romans. The sunken arena of the amphitheater was surrounded by the wall of a podium 2.5 m (8.2 feet) high, surmounted by a parapet. The presence of a 41.2-m- (135-foot-) long stage allowed scenes to alternate between theatrical productions and combat. A series of nine niches aided in improving the acoustics. Five cubbyholes were situated beneath the lower terraces, of which three appear to have been animal cages that opened directly into the arena. Historians believe that the terraces, which surrounded more than half of the arena's circumference, could accommodate as many as 17,000 spectators. When Lutèce was sacked during the barbaric invasions of 280 A.D., some of the structure's stone work was carted off to reinforce the city's defences around the Île de la Cité. Subsequently, the amphitheater became a cemetery, and then it was filled in completely following the construction of wall of Philippe Auguste (ca. 1210).
After the tramway lines and depot were dismantled in 1916 and line 10 of the Paris Métro was constructed, the doctor and anthropologist Jean-Louis Capitan (1854–1929) continued with additional excavation and restoration of the arena toward the end of World War I. The neighbouring Square Capitan, built on the site of the old Saint-Victor reservoir, is dedicated to his memory. Unfortunately, a portion of the original arena — opposite the stage — was lost to buildings which line rue Monge. Standing in the Centre of 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.