Classified as historical monument, the aqueduct of Arcueil-Cachan consists of three successive constructions. The first, dating from the Gallo-Roman age fed from Rungis and Wissous the baths of Lutece (Cluny), there are only two blocks of masonry left since. The second construction, the Medici aqueduct, was built of stone in the XVIIth century to feed the Left Bank of Paris and especially the Luxembourg Palace built by request of Marie de Medici. Finally the third construction, the Vanne aqueduct, was built in rubble by the engineer Eugene Belgrand in the XIXth century, it rests on the Medici aqueduct and leads the waters of Vanne (a tributary of Yonne) to the reservoir of Paris Montsouris. With a length of 990 m, the aqueduct has 77 arches of 10 m wide, it has a height of 38 m at the lowest point of the valley. Always in work, with a capacity of 145,000 m3 / day, the aqueduct supplies nearly a third of Parisians.