Plestin-les-Grèves (Municipality, Côtes-d'Armor, France)

The thermae of Hogolo, located on Pointe de l'Armorique, were built by the early Roman settlers of the place. Such buildings were probably common in Brittany, especially near the bays where the galleys could moor, but very few of them have been preserved until now. In 1892, a farmer ploughing his field excavated the foundations and parts of the walls of the thermae. The scientific study of the site started in 1938 but was stopped two years later. A villager of Plestin later rediscovered the hot bath building (caldarium), restored it and used it as his house until his death, in the late 1970s. The site was then purchased by the Department of Côtes-d'Armor, which revamped it completely and opened it to public visit in 1993.

The Irish prince and monk Efflam landed on the strand of Plestin in the Vth century. He was welcomed by the local ermit Jestin, said to be the origin of the name of the village: Plou [parish] Jestin. The ermit lived in an oratory built on the Grand Rocher (the Big Rock, in Breton, Roc'h Hirglas), a 84-m high rocky spur dominating the bay. Jestin and Efflam built a monastery, whose chapel housed the tomb of Efflam after the death of the saint in 512. The tomb was transferred in 994 in the early church of Plestin and later in the parish church, where Efflam's recumbent statue (1576) portrays him dressed like a king. In the past, crossing the bay was very hazardous because of the tides and the rascals who lived on the Big Rock, which was also known as Roc'h Ar Laz, the Murder's Rock.
The small port of Toul-an-Hery, located in the last curve of river Douron, was of significant importance in the Middle-Ages, when up to 15 ships were used for inshore fishing. The port was increased during the Ducal era but the first true landing stage, made in local granite, was built in 1847 only. Each year, some 100 ships moored in the port, shipping crop products and fuels, but also flaxware. Flax cultivation was very popular from the XVIIth century to the late XVIIIth century; the products were shipped to England and Spain, which allowed the emergence of a local aristocracy made of landlords and shipowners. Flax cultivation was abandoned in the middle of the XXth century and the port progressively silted up, being used today only for yachting.
Plestin lives today mostly from summer tourism, but is unfortunately often in the headlines in the papers because of the infamous green tides. Due to the increase in farming and pig-breeding, encouraged in Brittany in the 1980s without any thought about the environmental consequences, the quantity of nitrates released in the rivers has reached extreme levels. When temperature increases in spring, the nitrates accumulated in the bay trigger the proliferation of green algae, which constitute thick, stinky banks, making walking and resting on the beaches impossible. In 2003, the municipality collected and trashed more than 25,000 tons of algae from the beaches.