||The toponym "Arennes" is found in texts from the 12th century onward-indicating that the existence of such a monument as well as its location near Saint-Victor were always known. It was only in 1867-1868, however, during the construction of the Rue Monge, that Th. Vacquer-who knew that such a discovery was possible-began to excavate the amphitheatre.
In 1870, construction work on a warehouse for the Compagnie des Omnibus (a transportation firm) revealed a large portion of the edifice. A battle was waged to protect the remains, but three months later, the Compagnie was granted permission to tear them down.
||Other archaeological excavations were carried out on neighbouring plots of land in 1872 and 1883; Theodore Vacquer was excluded from these because of his difficult personality. Finally, following the intervention of a number of important people, including Victor Hugo, the city of Paris acquired the land and attempted to preserve what remained of the amphitheatre.|
In 1915-1916, the architect Jules Formigé carried out a "restoration"-tantamount to a reconstruction-based largely on guesswork. The remains were converted into a public park, accessible today by a door at 49 Rue Monge, and by the Rue de Navarre.