“Amongst those abuses which seemed to require reform, may be mentioned what took place regarding the supply to the Cœlian and Aventine hills. These hills, before the Claudian was supplied to them, were accustomed to use the Marcian and Julian; nevertheless, when the Emperor Nero gave them the Claudian raised to a greater height on the series of arches extending to the Temple of Claudius, where it was distributed, the older streams, instead of yielding an increased supply, were lost altogether. He made no new castella [for the Claudian], but used those which were there, and which retained their names, although the water brought to them was different[131].” THE RIVER ANIO. The highest source of the river Anio, or Aniene, is in a gorge in the highest part of Mount Cantaro, about 63 miles from Rome. This spring never fails in the hottest and driest weather, and is always cool; it is situated in the close or (_serra_) of St. Antonio, and is called _La Canala_, or the canal at the gate of the small castle or fortified village of Filettino. Pliny says[132] that it rises in the territory of Treba[133]. In going from Filettino towards Trevi the road has an ancient pavement, and on the left-hand side is a magnificent substructure of Cyclopean character called _Mura Saracine_, against the cliff. In 1857 Signor Gori saw some of the large stones of this fine ancient substructure thrown down to the banks of the stream, to make the foundations of a small bridge across it. The stream receives several accessions from other springs in its course, two from a cave called Pertusu, the small limpid stream called Suria, on the hill of Trevi, and another called Capo d’Acqua. The Anio thus augmented falls in two cataracts, or cascades, near Pertusu, and passes under the Ponte delle Tartare with much violence. This bridge is a natural arch of rock formed by the force of the water piercing it. The river then passes on through a gorge in the mountain-pass in small waterfalls, especially at a place called Pendema, where in 1855 an ancient mosaic pavement and a wall of reticulated masonry were found. At the two bridges of Communacchio (_comune acqua_), where an amphitheatre of mountains and the castle of Valle-pietra are situated, another stream coming from the mountains of the Trinitá and Autore, the highest in that district, joins the Anio.