France's Largest Artificial Lake Is A Serene Mountain Gem With Beaches, Boating, And Swimming Spots In The Alps

Striking natural wonders abound in the Alps. From the breathtaking peaks of Matterhorn and Mont Blanc to the enormous, icy sheets of the Aletsch Glacier and Mer de Glace, Europe's premier mountain range is a trove of Mother Nature's finest creations. But not every Alpine destination beckoning travelers to visit was naturally born of the terra firma. Case in point: Lac de Serre-Ponçon, France's largest artificial lake. This brilliant blue, man-made marvel is a haven for boating and water sports that's fringed with serene beaches for swimming, many of which have been deemed "Blue Flag" for their quality and safety. 

Nestled in southern France's Durance Valley along the border of the Hautes-Alps and Alpes-de-Haute Provence, Lac de Serre-Ponçon mixes fun in the sun with some very serious duties. Perched at an altitude of 2,560 feet and filled with 45 million cubic feet of water, this Alpine gem is actually a reservoir that was built alongside a dam in the late 1950s to stem decades of flooding from the Durance River. Today, this idyllic body of water does much more in addition to managing droughts and flooding. Lac de Serre-Ponçon powers Provence with renewable energy, while also supplying it with drinking water and water for irrigating farmland. 

Experience the lake's charms by dipping in its blazing azure waters. Swim out from the shores of its pristine beaches, or use it as a spot to cool off from a hike. Boat out to see the floating Saint-Michel Chapel, relocated here during the reservoir's construction. Travelers can also revel in lake panoramas from numerous trails, roads, and overlooks. As one awestruck visitor shared on Tripadvisor, "The green hue of the water, fed by the Ubaye stream, is reminiscent of tropical paradise."

Just as beautiful beaches encircle France's largest, deepest natural lake, the Alpine Lac du Bourget, beaches also surround the country's largest artificial lake. Lac de Serre-Ponçon boasts several Blue Flag stunners, from beaches studded with floating aqua parks to untamed nature escapes. The most serene lakeside beaches, like the unspoiled Port Saint-Pierre Beach (the first on the lake to receive a Blue Flag), tend to be on its southern end, close to where the lake meets the Ubaye River. Livelier beaches like Saint-Michel Bay, Embrun, and Crot stretch from the center of the lake to the north. One of the lake's most unique swimming spots are the two floating, wooden-framed pools (one for adults and one for kids) at Bois-Vieux Beach in Rousseau Serre-Ponçon. Both pools sit directly on the lake and are filled with lake water.

The lawn and pebble beach of Trémouilles on Chanteloube Bay is one of the lake's most peaceful. Separated by dramatic coves from Saint-Michel Bay, it's a great swimming spot graced with views of the majestic Pic de Morgon. Across the lake lies Ubaye Beach, another swimming beach with panoramic views of Pic de Morgon. Relaxed, family-friendly Ubaye boasts light amenities like a volleyball court, playground, and snack bar. It's also one of several beaches on the lake equipped to accommodate visitors with reduced mobility. Decked out with a skate park and picnic area, sprawling Combettes Beach is generally uncrowded, promising a calm, leisurely day on the water. 

For hikers, scenic trails surrounding the lake offer great views before or after a cooling dip. The pine tree-studded Belvedere Le Sauze-du-Lac loop ends at a cove at Port Saint-Pierre. Another option is the mountainside trail that follows the railroad tracks from Chorges down to the lake, where a swim in the Saint-Michel Bay awaits.

Boating is a wonderful way to take in some of Europe's most underrated lake destinations, and Lac de Serre-Ponçon is no exception. The lake is exceptionally boat-friendly, boasting 10 public harbors and over 1,200 moorings as well as boat launches, slipways, and fueling stations at numerous beaches. Both licensed and unlicensed sailors can rent a variety of motorized and non-motorized boats at several places around the lake. Alternatively, head over to the port of Savine-le-lac and book a guided boat tour or a laid-back lake cruise.

Gliding across the lake showcases staggering Alpine views and takes you right up to some of the most unmissable sites. Cruise out to the lake's center to visit the medieval Saint-Michel Chapel, one of the lake's most emblematic landmarks. There's no mooring allowed on the chapel's verdant isle and the interior is closed to visitors, but you'll get close enough to admire its Romanesque architecture. There's also the Chanteloube viaduct, the fascinating remains of an abandoned railway project. You'll see it submerged underwater in summer, although it peeks above the water during other seasons depending on the lake's level.

Boats are also handy for discovering hidden, natural treasures that are only reachable by water. Navigate the striking, secret coves separating the bays of Saint-Michel and Chanteloube, then zip over to see the solitary, cliffside oak tree hovering over the lake at Bois Vieux Beach. You can also motor around Turtle Island, a lush, pine tree-covered islet with a shape that resembles the animal's shell. The best time to visit Lac de Serre-Ponçon is in the summer months of June through September when water levels and lake temperatures are best for swimming and boating. For more incredible mountain scenery in the region, visit France's "Venice of the Alps," Annecy.