ANIO, or ANTEN, the modern TEVERONE, one of the most considerable tributaries of the Tiber, rises in the Apennines, about three miles above Trevi; and flowing first in a north-western, and afterwards in a south-western direction, joins the Tiber three miles above Rome. In its course it receives several small rivulets, among which is the Digentia of Horace, now the Licenza; and at Tibur it forms a beautiful cascade, originally the work of the Romans. The waters of the cascade are now carried through a tunnel constructed in 1834. Rome was supplied from this river, on account of the purity of its water, by means of two aqueducts, called the Anio vetus and Anio novus.