Some distance away from the cycle route, between Vallorbe and little Lake Brenet, you will find the dripstone caves of Vallorbe. Surrounded by stalactites and stalagmites, you plunge down into a different kind of world where the mercury stays at a cool 10 degrees. The roaring waters of the Orbe flow underground here before they emerge from the mountain at another point. But you'll not find it easy to "go with the flow" on your cycle now: the uphill forest track is rather bumpy. The striking Dent de Vaulion peak (1,483 meters) is nearby, but you can't see it for trees. You also have to use your imagination to picture Europe's largest ice-skating rink – you can hardly expect Lake Joux to be frozen over when you take your cycle tour. There is a small but excellent cheese museum at Les Charbonnières. The Vacherin Mont-d'Or Museum pays tribute to the famous soft cheese from the Vallée de Joux: Les Charbonnières is the birthplace of this delicacy, which is only produced between August and March.

As you leave the cool clear charms of Lake Joux behind you, it's already time for another bracing uphill section. And wherever there are mountains, there are also passes. But wherever there are passes, there are also motorbikes that make cyclists' ears ring as they zoom past. You leave the main road before the top of the Col du Marchairuz pass, and then you traverse the stunningly beautiful countryside of the Jura Vaudois Nature Park in the far west of Switzerland. Covering 530.6 km², this regional park was inaugurated in 1973: it consists of a mosaic of forests, meadows, moors, sinkholes (funnel-shaped karst depressions), karst rocks and huge anthills, with a few Alpine chalets scattered here and there.

There could hardly be more contrasts on the descent towards Lake Geneva. Blossom-strewn wheatfields, vines and pretty wine-growing villages create a Mediterranean ambience. On reaching the village of Bassins, pause to admire the "Six Historic Fountains of Bassins". The oldest mention of these fountains dates back to 1688. If you haven't entirely drained your batteries after this long and intensive stage, you should take time to visit its destination: the town of Nyon. An enchanting castle, 16th-century townhouses and the Lake Geneva Museum directly on the shore make a stopover well worthwhile. Fans of pop and rock music are likely to be familiar with Nyon because of the annual Paléo Festival staged here at the end of July.