The Vallée de Joux (pronounced as /fr/) is a valley of the Jura Mountains mainly in the Swiss Canton of Vaud. The valley also continues into France (Jura département) at its higher, southwestern, end. Located north of Geneva and northwest of Lausanne, its mean elevation is over . There are three Swiss lakes in the Vallée de Joux: the lac de Joux (around long), the lac Brenet and Lake Ter. The French border runs along the northern edge of the valley until, about west of the lac de Joux, the base of the valley becomes French territory. The valley then continues to climb gently towards the Lac des Rousses and the ski resort of Les Rousses.
The NE-SW orientation, and the 1000m (3,000feet) altitude combine to make for an especially cold winter climate. Indeed, the valley is sometimes called the Vaud Siberia. The coldest weather arises when the Bise wind, which comes from the North-East, is blowing.
There are three main municipalities in the valley, le Chenit, le Lieu and l'Abbaye, all part of the Jura-Nord vaudois District. These include ten villages, such as Le Sentier, Le Brassus, Le Lieu and Le Pont.
The Vallée de Joux is, along with Neuchâtel, the birthplace of Swiss horology and it is still the home of the most famous Swiss watch factories, like Audemars Piguet, Blancpain, Breguet, Patek Philippe, Vacheron Constantin and Jaeger-LeCoultre.
The Vallée de Joux hosts four ski resorts, a common forfeitary offer is available:
Vallée de Joux is the largest ski area in the Swiss Jura.