THE CLOACA MAXIMA,
or great drain, begun by Tarquin the Great, containing a large stream of water rushing along, as it did over two thousand years ago, is exposed to view at the east end of the Basilica Julia.
It was finished by Tarquin the Proud, B.C. 556 (Livy, i. 38, 55).
"Men spoke in admiration of the public sewers, too, a work more stupendous than any, as mountains had to be pierced for their construction, and navigation might be carried on beneath Rome; an event which happened in the ædileship of M. Agrippa, after he had filled the office of consul." (See Dion Cassius, "Augustus," A.U.C. 721.)
"For this purpose there are seven streams turned into the artificial channels, and flowing beneath the city. Rushing onward, like so many impetuous torrents, they are compelled to carry off and sweep away all the sewerage" (Pliny, xxxvi. 24).