Lac de Chalain is the largest natural lake in the French Jura, a long, green-blue lake set in a valley among forested limestone cliffs, and its shores were home to farming villages built on piles thousands of years ago. The remains of these villages, preserved in the lake bed, are part of the Prehistoric Pile Dwellings around the Alps, listed by UNESCO in 2011. In the 1900s, when the lake level was lowered for a hydroelectric project, a dugout canoe and the remains of houses were found, and excavations since then have revealed a remarkable picture of life in the Neolithic.
Today, the lake is a popular spot for swimming, boating and camping in summer, with a beach and a large campsite on the shore. The surrounding area is the Region of the Lakes, the Pays des Lacs, a plateau dotted with small lakes, forests and waterfalls. The Cascades du Hérisson, a series of waterfalls on the Hérisson river, are among the most beautiful in France, and a trail leads up the valley past them. Nearby, the Belvédère des Quatre Lacs offers a view of four lakes from a cliff top.
For riders, the Jura is a delightful region, with quiet, well-surfaced roads winding through forests, valleys and pastures, gentle bends and moderate gradients, and little traffic outside the summer holidays. The roads around the lakes, between Clairvaux-les-Lacs, Doucier, Ménétrux-en-Joux and Champagnole, are particularly scenic, with views of lakes and cliffs. Further east, the roads climb toward the high plateaus and the Swiss border, through the Forêt de la Joux, one of the finest fir forests in France.
The climate here is cool and wet, with cold winters and snow on the high plateaus, and the roads can be slippery in rain. Summer is the best time to visit, though the area is busy in July and August.
Champagnole, about thirteen kilometres away, is a small industrial town on the Ain with fuel, supermarkets and a few restaurants; Clairvaux-les-Lacs is smaller but has a station and cafés in season. Pack a picnic, because the best lunches here are eaten on a rock above the water: a loaf from the bakery, a wedge of Morbier with its thin line of ash through the middle, and a bottle of cold water from the spring. If you want a proper meal, look for poulet aux morilles, chicken in a cream sauce with morel mushrooms gathered from these forests, and save the swim for after, once lunch has settled.