If brooks and rivers run only sluggishly above ground, hydropower is nearly impossible to harness. That is why the inhabitants of the valley of Le Locle began to use subterranean streams. This is how the cave mills of "Col-des-Roches" arose.

It defies the imagination how the subterranean factory was set up 400 years ago. And yet the water-powered mills and the sawmill exist, in natural and artificial tunnels and karst caves. The cave factory, which is the only one in Europe, was restored by volunteers and is open to the public today.

The subterranean mills illuminate an entire epoch of regional history. A museum about the functioning and the role of the mills illustrates the use of hydropower and enables visitors to gain insight into the special character of the Jura. In the grottoes and in the tunnels one can view the restored mill and sawmill mechanisms.


The cave is cold and has an average temperature of 7°C, bring a woolly sweater!

General information

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All year
Time required
2 to 4 hours (half day)
Suitable for children with age
10 to 13 years, 14+ years
Suitable for
Groups, Individual, Couples
Indoor and outdoor
Education, Adventure

Group & pricing information

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German, English, French, Italian, Spanish
Group Size
1 - 25

Discover the surroundings


Les Moulins souterrains du Col-des-Roches
Le Col 23
2400 Le Locle

Phone  +41 (0)32 889 68 92
Fax +41 (0)32 889 63 02



Le Locle
Jura & Three-Lakes
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Les Moulins souterrains du Col-des-Roches
Le Col 23
2400 Le Locle
Phone  +41 (0)32 889 68 92

Travel information: Le Locle

Discover Le Locle