The Nera, which rises in the lofty group of the Monte della Sibilla, is a considerable stream, and brings with it the waters of the Velino (with its tributaries the Turano and the Salto), which joins it a few miles below its celebrated waterfall at Terni.
The principal towns are Montevideo, Salto, Paysandu and San Jose.
Since 1890 the cultivation of the grape and the manufacture of wine have considerably extended, especially in the department of Salto, Montevideo, Canelones and Colonia.
Many of the factories derive their motive power from the falls of a mountain torrent known as the Salto de las Aguas.
Between the western and central ranges are the plain of Rieti, the valley of the Salto (Himella), and the Lago Fucino; while between the central and eastern ranges are the valleys of Aquila and Sulmona.