Couesnon (fleuve) walks

The Couesnon river meanders through a deep valley, home to ancient mills.

This route of the Couesnon can be divided into two parts: a circular route to the west and another to the east, the latter of which can be shortened. The Couesnon has a very winding course as it crosses the granite massif. Its limestone-free water was used for a long time in paper mills in the 17th century. With this industry now gone, the Couesnon is a delight for salmonids and kayakers alike.

4-hour hike (hence its medium difficulty). A little road and quite a few paths. You will cross the Couesnon and Minette valleys.

After walking along the Couesnon, which is calm and peaceful on this section, walkers are invited to discover a small stream that feeds it: the Vallées d'Hervé stream. Then, despite a few open sections, walkers will appreciate the peaceful shade of the undergrowth and sunken paths.

Halfway between the national forest and the hillsides of the Eure, this walk will take you to some remarkable places in the shade of oak trees and the coolness of the riverbanks. You will walk past the castle and through the old village of Sorel, then follow the old railway line (greenway) to Marcilly-sur-Eure.

This walk takes you along the Couesnon between the dam and Anse de Moidrey, where you can see the polders on the Brittany side and the abundant wildlife, especially birds.A little history: formerly known as Lerra Fluvius, the Couesnon river rises in the commune of Saint-Pierre-des-Landes in Mayenne, at the Fontaine de Couesnette, 200 metres above sea level. The Couesnon was canalised in 1867, allowing boats to travel up the river to the port of Pontorson. The first dam, built in 1969, was designed to stop the tide from rising in the riverbed, which caused flooding when the tidal coefficients were high. It was demolished in 2008 and replaced by the Couesnon Dam as part of the operation to restore the maritime character of Mont-Saint-Michel. Please note that the footbridge at the car park is closed until 31/06/2026 due to construction work (see alternative in practical information).