The Jura plateau behind Clairvaux-les-Lacs is a country of limestone, cows and lakes, and the Grand Lac de Clairvaux is the largest of the lakes that give the town its name. Prehistoric people lived on its shore on pilings, in villages that rose and fell for centuries, and the waterlogged mud preserved their wood and tools. The sites on Clairvaux's lakes are among the pile-dwelling places inscribed on the UNESCO list in 2011. The lake today is a quiet blue sheet, ringed by reeds and low wooded hills, with a beach where families swim in July.
It is a gentle stop but the country around it is far from flat. The Jura here rolls in long folded ridges, and the roads cross them in loops and climbs: the D678 and its neighbours twist between pastures, spruce forest and villages with stone farmhouses and broad roofs. Surfaces are generally good, and the bends are the right kind, open enough to carry speed and tight enough to keep you awake. Cowbells ring from the meadows in summer, and the farms smell of hay and cheese.
Food is half the point of the region. This is Comté country, where the great wheels of cheese ripen in cellars for months or years, and the Jura also makes vin jaune, a nutty, oxidised yellow wine aged under a veil of yeast, best served with chicken in cream and morels. Château-Chalon, a hilltop village not far away, is the home of that wine. Clairvaux-les-Lacs itself is a small town of about fifteen hundred, with shops, restaurants and a fuel stop, and Lons-le-Saunier to the north is the bigger place to fill the tank properly.
Within an easy ride lies the Saline Royale at Arc-et-Senans, the great semicircular salt works designed by Claude-Nicolas Ledoux in the 1770s, another World Heritage Site, and the waterfalls of the Hérisson valley, just east. Spring and early autumn are lovely, with clear light and fewer visitors. Winters are cold and snowy at altitude, and roads over the higher ridges can ice up, so choose your season with care.