Beginning from the group called the Alpi della Luna near the sources of the Tiber, which attain 4435 ft., they are continued by the Monte Nerone (5010 ft.), Monte Catria (5590), and Monte Maggio to the Monte Pennino near Nocera (5169 ft.), and thence to the Monte della Sibilla, at the source of the Nar or Nera, which attains 7663 ft.
Sepolcro and CittÃ di Castello, then between Perugia and Todi to Orte, just below which it receives the Nera.
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 Teverone or Anio, which enters the Tiber a few miles above Rome, is an inferior stream to the Nera, but brings down a considerable body of water from the mountains above Subiaco.
above the Nera valley, at the point where the river traverses a narrow ravine, and commands a fine view.