At 1,004m altitude, Lac de Joux sometimes freezes over in winter, becoming the largest natural ice rink in Europe.
Speaking to 20 Minutes on Friday, the director of tourism in the area said the entire 9.2km2 lake wasn't frozen, but that a section the size of 15 football pitches was frozen enough for skaters.
But he warned not to stray from the designated areas.
Lac de Joux may be the biggest but it's not the only natural rink in Switzerland.
Also in the Jura, skaters have already taken to the frozen Lac des Rousses and the Lac des Tailleres, near the ‘Swiss Siberia' of La Brevine.
Elsewhere, the frozen Oeschinensee is open to hikers, skaters and ice-fishers, as is the 2,000m2 Seehofseeli in Davos.
Always check the conditions before you set foot on the ice and obey signage and safety warnings.
Temperatures are set to stay below zero across much of the country in the coming days.