Barrage sur le Couesnon - Beauvoir walks

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).