Semnon
The Semnon is a long river in the Mayenne, Maine-et-Loire, Ille-et-Vilaine and Loire-Atlantique départements, western France. Its source is at Congrier. It flows generally west-northwest. It is a left tributary of the Vilaine into which it flows between Pléchâtel and Bourg-des-Comptes.''Départements'' and communes along its course
This list is ordered from source to mouth:
- Mayenne: Congrier, Saint-Erblon, Senonnes
- Maine-et-Loire: Pouancé
- Ille-et-Vilaine: Eancé, Martigné-Ferchaud
- Loire-Atlantique: Fercé
- Ille-et-Vilaine: Thourie
- Loire-Atlantique: Soulvache
- Ille-et-Vilaine: Teillay, Ercé-en-Lamée, Lalleu, Tresbœuf, La Bosse-de-Bretagne, Bain-de-Bretagne, Pancé, Pléchâtel, Poligné, Bourg-des-Comptes