It is the largest lake in the Jura mountain range.
During harsh winters, the lake is officially declared open for ice skating, becoming one of the largest natural rinks in Europe.
The lake has no natural surface outlet; its water drains through underground limestone fissures and reappears at the source of the Orbe river.
The water level is regulated by a dam constructed at the end of the 19th century to supply power for local watchmaking industries.
The lake's water is notoriously cold, rarely exceeding 20°C even during peak summer months.
It is home to the specific endemic 'Joux trout' species.
Lac de Joux is the largest body of water in the Jura Mountains, situated at an elevation of 1,004 meters above sea level. Fed primarily by underground springs and the Orbe river, the lake acts as a natural reservoir that occasionally freezes completely in winter, creating an expansive natural ice rink. Its location within the Vallée de Joux makes it a primary destination for sailing and windsurfing due to consistent thermal winds. The lake depth averages 14 meters, reaching a maximum of 32 meters. The surrounding landscape is dominated by dense forests and limestone terrain characteristic of the Swiss Jura. The area is a hub for high-altitude sports training and outdoor recreation.
The shoreline near the village of L'Abbaye looking toward the Dent de Vaulion mountain.
Bring layers, as the high elevation leads to rapid temperature drops even in mid-summer.
Check the official local municipal website for the current status of water activities or ice thickness before arrival.
Utilize the designated swimming areas rather than swimming near the dam or boat channels.
Do not attempt to walk on the ice unless it has been officially declared safe and open by the local municipality.
Sailing and water sports are active from late spring through early autumn; ice skating is entirely weather-dependent and seasonal.
Maintain silence near protected nesting areas; use marked paths to prevent erosion of the shoreline.
