The Vallée de Joux with the eponymous lake lies nestled between two ranges of the Jura. With its rugged, unspoilt natural environment, the valley is also known as the cradle of watchmaking. The edge of the village of Le Pont reaches Lac Brenets, while the village's houses form a circular arc around the waters of Lac de Joux. Especially eye-catching are the different building façades, separated by narrow alleyways. Behind them are courtyards, gardens and orchards. And farther in the distance: a breathtaking, hilly landscape where this hike will now take you.

Starting from the shore of Lake Joux, a steady climb leads via La Dent to La Petite Dent. At times, you hike across pastured woodlands, through the forest or past dry-stone walls – typical Jura scenery. From Chalet de la Dent de Vaulion, the eponymous peak (1,483 metres above sea level) is easily and quickly accessible. The slopes of Dent de Vaulion are mainly covered with pine forest. In contrast, the summit features the sparse grassy vegetation of the Haut-Jura. A marvellous vantage point offers panoramic views over up to eight lakes in good weather, including Lakes Neuchâtel, Biel, Murten and Geneva, three lakes in the valley and Lac de Rousses in neighbouring France. The Alps and the Mont-Blanc massif surround this fabulous backdrop.

After a refuelling stop at the Buvette, your hike continues along the ridge before entering the forest. Downhill through the Bois de Pétra Félix, you reach the fortification of the same name. The Petra Félix of the border brigade 1, which existed 1938-1994, is of national importance and lies west of the Mollendruz pass. It served as a checkpoint for the road from Le Pont and Vallorbe at the turn off to Vaulion-Romainmôtier and L’Isle-Cossonay. The path continues over pastured woodlands before ending back on the lakeshore in Le Pont.