The Vermenagna is a 27.1-kilometre (16.8 mi)[1] long river in northwestern Italy (Piedmont).

The Vermenagna is a tributary to the river Gesso, in the river Po basin.

Its source is a small lake higher than 2000 m close to the Rocca dell'Abisso, not faraway from the Colle di Tenda; after Limonetto the flows crosses the comunes of Limone Piemonte and Vernante, where it gets from the left bank its main tributary, the rio di Valle Grande, which collects the waters of the valley of Palanfrè (or ‘’Val Grande’’).

Its course continues reaching Robilante and Roccavione; on the border between the latter comune with Borgo San Dalmazzo the Vermenagna ends in the Gesso, at 610 of elevation.

[3] Media related to Vermenagna at Wikimedia Commons