For 10 points, name this underground drainage channel of Ancient Rome, whose name is Latin for "Greatest Sewer".
A statue of Cato the Elder was erected in the Temple of Salus to honor Cato's restoration of this structure, which according to Dionysius cost Cato a thousand talents to repair. In his Natural History, Pliny the Elder criticized historians for "passing over in silence" the fact that this structure had lasted for seven hundred years and said it was the idea of Tarquin the Elder, while Livy lists the building of this structure, as well as the construction of seats in the Circus, as a project for which Tarquinius Superbus used forced labor of the plebs. Historians dispute when this structure, which was probably built open to the air, first became enclosed, and it probably merged with seven smaller structures at the Janus Quadrifrons. The construction of this structure created the first usable public space  for the Forum, which is now directly above this structure. This structure was instrumental to the running of the public baths, whose runoff it carried to the Tiber. For 10 points, name this underground drainage channel of Ancient Rome, whose name is Latin for "Greatest Sewer".
A statue of Cato the Elder was erected in the Temple of Salus to honor Cato's restoration of this structure, which according to Dionysius cost Cato a thousand talents to repair.
Cloaca Maxima [prompt on "Cloaca" or on "sewer" or "sewage system"]