On the frontier between the sea and the land, from the 12th century the first sea mills (Milin-mor ou Meil-mor) were built along the coasts of Brittany, but their construction developed principally during the 16th and 17th centuries.
Their appearance is linked to the development of craft industries and the development of the growing of Saracen. Industrial flour-mills built on four to five floors only followed them in the 19th century.

Built on the tidal region at the top of estuaries or of bays drawn back from the coast, these mills which worked under the rhythm of the tides demonstrate the very ancient use of energy created by the ebb and flow of the tides. The wheels and the millstones worked on the ebbing tide, thanks to the water accumulated behind a dike during the rising tide.

The amplitude of the tides explains the fact that Brittany was the principal region of France to use this energy source, with nearly a hundred active buildings unevenly distributed accross the littoral.
Left to neglect during a long period, this industrial heritage is now the subject of intelligent restoration. Some mills, now shelter restaurants or second homes.

The Emerald Coast, renowned for its spring tides (15 m tidal range) is the region of Brittany where the greatest number of stone buildings, recalling the architecture of peasant homes, is concentrated. There are no less than seventeen on the edges of the two shores of the Rance. At the same time as great a number circles the Etel ria and the Gulf of Morbihan.
The only tidal power station in France (500 millions de kw/h par an) built on the Rance between Dinard and Saint-Malo, works since 1966 on the same principles as the former sea mills.

What to visit:
The Mills of Perros-Gurec, Bréhat, Trégastel, Pleudaniel, Muzillac, Sarzeau, Arzon, Le Hézo, Arradon, Baden, Le Bono.