Anio

Chambers's Encyclopaedia, Volume 1: A to Beaufort, p. 290

Anio, the ancient name of the Teverone, a tributary of the Tiber, which rises in Monte Cantaro, and joins the larger river 3 miles above Rome. Its beautiful cascade at Tivoli (the ancient Tibur) is celebrated by the classical poets. Owing to the purity of the stream, Rome was from 270 B.C. supplied with water from it by means of two aqueducts.

Source scan(s): p. 0309