From the Ferriere Bridge, under Montelone di Spoleto, the Corno River starts to flow between steep woody sides, separating the ridges of Mount Meraviglia (1392m) and Mount Pizzo (1438m) to the east, from Mount Roccaporena (1149 m) to the west.

The river and the valley bottom meander northwards between rocky outcrops which overhang the fields and ploughed meadows or terminate directly on the riverbanks, creating true canyon-like shapes in different sections. A short distance beyond a narrow ravine, the river laps the Sacred Cliff of Roccaporena. It is better to climb back up, along the 120 metres of the Sacred Cliff that faces the crags and the formations overhanging the inhabited centre, and then travel, departing from the base of the Cliff to Cascia, on the so-called Trail of Saint Rita, a flat road which crosses the entire right side of the valley, at many points directly above the crystal-clear river water. Descending on foot into the valley floor, it is possible to discover corners of particular beauty and admire enchanting sections of the fluvial banks.

From Cascia onwards the River Corno continues in a wider valley bottom and in Serravalle (500m) it receives the water of the River Sordo, coming from the water-meadows of Norcia. The entire fluvial course from Serravalle to Triponzo is flanked by the route of the former Spoleto-Norica railway line, which offers the opportunity to admire the fluvial valley from an unusual perspective through the magnificent views of the tunnels.

The convergence between the Corno and the Nera, at Triponzo, is a location of rare beauty, where the rocks rise directly from the fluvial banks creating some of the most beautiful gorges and ravines in Umbria, like those of Biselli in Balza Tagliata.

The fauna and flora along the entire course of the river is of considerable interest.