Here the road joins the railway line through the tunnel, which is 124 m.
The Ballycastle railway joins the main line here.
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 Am, the, Sane (which rises in the Faucilles and in the lower part of its course skirting the regions of Bresse and Dombes, receives the Doubs and joins the Rhone at Lyons), the Ardche and the Gard are the affluents on the right; on the left it is joined by the Arve, the Isre, the Drme and the Durance.
The principal affluents are the AriCge, the Tarn with the Aveyron and the Agout, the Lot and the Dordogne, which descends from Mont Dore-lesBains, and joins the Garonne at Bec-dAmbez, to form the Gironde.
