Lac de Guerledan, Brittany, France

Also known as:  Lake Guerledan

Welcome to the ultimate guide for history, statistics, local fun facts and the best things to do at Lac de Guerledan.

If you’re considering Lac de Guerledan vacation rentals, we’ve made it super easy to explore accommodations and nearby hotels using the interactive map below. Simply click on a listing to compare similar properties, best rates and availability for your dates. Or keep scrolling to read our Lac de Guerledan guide!

Lac de Guerledan visitor and community guide

Lake Locations: France - Western France - Brittany -

Lac de Guerledan is the largest lake in Western France’s Brittany tourism region, situated deep within the Argoat forest. The artificial lake is a family-friendly destination formed where the Blavet River meets the Nantes-Brest canal. This French waterway connects the municipalities of Brest and Nantes, and is navigable from Lake Guerledan. It stretches for an impressive 209 miles and features 158 locks.

The construction of Lac de Guerledan’s hydroelectric dam was begun in 1923 when engineers changed the flow of the Blavet River, but not completed until 1930 when the dam was finally put into service. The dam stands 155 feet high and 660 feet wide, and serves to provide hydroelectric power and flood control to surrounding regions. Every ten years the dam is drained for maintenance, and the city that used to exist beneath Lake Guerledan – formerly known as Ys – is revealed like magic.

Lac de Guerledan has a surface area of 988 acres and a normal elevation of 397 feet above sea level. With a maximum depth of 164 feet, it is known for both its aesthetic appeal and its wide array of water sports and recreational activities.

The irregular shores at Lac de Guerledan are perfect for carp fishing. Anglers reel in catches of pike, trout and perch populations at Guerledan Lake and its surrounding rivers. Zander, a species of fish that looks like a cross between pike and perch, is known to reach weights of up to 20 pounds here; most weigh between three to seven pounds.

Alternatively, visitors can spend a relaxing afternoon canoeing, kayaking and soaking up the sun along Lac de Guerledan’s sparkling beaches; adventurous types might try rock climbing one of the nearby gorges. For mountain biking enthusiasts, there are almost 300 trails in the area – but in France it is known as VTT, which stands for Velo Tout Terrain.

An on-site sailing school with water ski and pedal boat rentals makes for an exciting and educational afternoon at Lac de Guerledan. Canal boats known as ‘vedettes’ are also available to take visitors on peaceful sightseeing tours around the lake. Golfers should play a round at one of the local 18-hole championship courses, while trailblazers could spend an eternity hiking along the endless trails of the Argoat Forest. Horseback riding and ATV trails are also available for public use.

Several interesting towns and landmarks surround Lac de Guerledan. Head to Pontivy, Rostrenen and Quintin for a shopping fix, or to Mur de Bretagne’s Friday night evening market. During the summer, Breton hosts a number of dances and music festivals, the most famous of which is Fest Noz, or “Festival of the Night.” In Medieval times, this celebration was designed to encourage dancers to stomp their feet to firmly pack down a freshly-made floor. Fest Noz and St Gilles Vieux-Marche are held in July, and the Mur de Bretagne in August.

For a great day trip from Lac de Guerledan, check out the Armorique Regional Natural Park. Established in 1969, this reserve is the second oldest protected park in the history of France. It is composed of 425,000 acres and covers four distinct areas: the Iroise Sea islands, the Crozon Peninsula, the riverl Aulne, and the rocky Monts de’Arree. UNESCO calls the Molene archipelago, which is home to Europe’s largest seaweed field, “the reserve of the biosphere” for its rich wildlife and populations of seals and bottlenose dolphins.

Another nearby site of interest is the dolmen specimens at Liscuis, just a few minutes from Lac de Guerledan. These prehistoric tombs are composed of long, flat stones balanced on top of upright ones. The town of Saint-Aignan is home to a museum of electricity, which teaches about the history and science behind the Guerledan dam. If you are looking for a party, the best place to go for an upbeat nightlife scene is Pontivy. The largest city in the area, Pontivy, boasts an array of restaurants and pubs.

Real estate properties and vacation rentals are available around Lac de Guerledan, some on 19th century farms with homegrown fruit and vegetables. Come see Lac d’Guerledan for yourself to experience nature and make long-lasting memories.

Custom Lac de Guerledan house decor

Read our full review of these personalized lake house signs.

Things to do at Lac de Guerledan

  • Vacation Rentals
  • Fishing
  • Boating
  • Sailing
  • Swimming
  • Beach
  • Canoeing
  • Kayaking
  • Water Skiing
  • Golf
  • Hiking
  • Rock Climbing
  • Biking
  • Horseback Riding
  • Wildlife Viewing
  • Museum
  • Shopping

Fish species found at Lac de Guerledan

  • Carp
  • Perch
  • Pike
  • Trout
  • Zander

Best hotels and vacation rentals at Lac de Guerledan

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Lac de Guerledan photo gallery

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Lac de Guerledan statistics & helpful links


Lake Type: Artificial Reservoir, Dammed

Water Level Control: EDF, Electricite de France

Surface Area: 988 acres

Normal Elevation (Full Pond): 397 feet

Maximum Depth: 164 feet

Water Volume: 44,589 acre-feet

Completion Year: 1930

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