Aqua Anio Vetus

The Aqua Anio Vetus was a Roman aqueduct, commissioned in 272 BC by censor Manius Curius Dentatus and funded from the war booty seized after the victory against Pyrrhus of Epirus[1]: 29 [2]: 148 .

[5] Like the Aqua Appia, its route was mainly underground, but it emerged at many points to cross river valleys especially after bridges using better technology were later used to shorten its course considerably.

Other restorations in the first two centuries AD include the construction of bridges across valleys on the route to shortcut long underground diversions.

[9] Earlier routes of the aqueduct passed over two other bridges starting higher upstream which were successively abandoned when they became excessively damaged.

The bridge is made of Roman concrete covered with opus reticulatum with the use of tufa blocks in the abutments and brickwork for the arch.

It has a notable asymmetry due to the connection with the original channels at each end which were of widely different levels at this point in the valley as they previously followed a long loop.

The water apparently acted as a lubricant between these structures and, probably in conjunction with a flash flood or earthquake, the travertine block slid downstream, causing the bridge to collapse.

[11] At the bottom of the gorge are two rooms dug out of the tuff bank which were most likely used to house workers during aqueduct construction and completely submerged when the dam was built.