A reservoir isn't the most obvious summer holiday pick — until you see this one. Lac de Serre-Ponçon, straddling the Hautes-Alpes and Alpes-de-Haute-Provence in southern France, is the largest artificial lake in the country, sitting at around 2,560 feet of altitude and holding roughly 45 million cubic metres of water. It was created in the late 1950s when a dam was built on the Durance River to tame decades of flooding, and it still works hard today: managing floods and droughts, generating renewable energy for Provence, and supplying drinking and irrigation water.
None of that utility has stopped it from becoming a genuine beach destination. Several of the lake's shores carry Blue Flag status for water quality and safety. The quieter stretches — like Port Saint-Pierre, the first beach here to earn a Blue Flag — sit at the southern end near where the Ubaye River feeds in, while livelier spots such as Saint-Michel Bay, Embrun, and Crot run up the centre and north. One of the most unusual swimming setups is at Bois-Vieux Beach, where two wooden-framed floating pools, one for adults and one for kids, are filled directly with lake water. Trémouilles, on Chanteloube Bay, is a lawn-and-pebble beach with views of Pic de Morgon, and family-friendly Ubaye Beach offers a volleyball court, playground, snack bar, and facilities for visitors with reduced mobility. Sprawling Combettes Beach, with its skate park and picnic area, rarely feels crowded.
If swimming isn't enough, the lake is a boater's dream. There are ten public harbours, more than 1,200 moorings, plus slipways and fuel docks at beaches around the shore. You can rent motorised or non-motorised craft whether or not you hold a licence, or book a guided tour or cruise from the port of Savines-le-Lac. The water is also the only way to reach some of the lake's best sights: the medieval Saint-Michel Chapel on its own islet (no mooring, no interior access, but the Romanesque exterior is the lake's signature image), the half-submerged Chanteloube viaduct — an abandoned railway project that disappears under the summer waterline — the hidden coves between Saint-Michel and Chanteloube bays, Turtle Island, and the lone cliffside oak at Bois Vieux.
Hikers get their share too. The pine-forested Belvédère Le Sauze-du-Lac loop ends at a cove at Port Saint-Pierre, and a mountainside trail from Chorges follows the old rail line down to the lake, finishing with a swim in Saint-Michel Bay.
Plan for June to September, when water levels and temperatures are at their best. And if you're building an Alpine lake itinerary, Annecy — France's so-called Venice of the Alps — makes a natural companion stop.
For anyone who assumed the French Alps are all peaks and glaciers, this man-made lake is proof the region does beach holidays too.
Story via Islands.