Scialet de Malaterre

Scialet de Malaterre is a vertical karst shaft tucked into the Vercors massif, within the boundaries of Villard-de-Lans in the Isère department of France. Its entrance drops a sheer 120 metres, making it one of the most frequented caving sites in the whole massif. The word "scialet" is simply the local Vercors dialect term for a vertical sinkhole or karst pit.

Where is it located?

The shaft opens in the Malaterre forest, also known locally as the Loubière forest, at roughly 1425 metres of altitude. IGN maps place it about 800 metres west of the Malaterre mountain hut, on land belonging to the commune of Villard-de-Lans, deep inside the Vercors massif.

How deep does the cave go?

The entrance pitch alone is a 120-metre free drop. The first explorers reached a depth of 159 metres back in 1936. It took decades before anyone went further: in 1969 a team squeezed through a narrow S-shaped constriction and broke through to new passages, pushing the known depth to -200 metres. Beyond that point they found roomy galleries and a large chamber, with the lowest surveyed point sitting at -230 metres. The cave's total surveyed length is estimated at around 1600 metres.

Who first explored it?

André Bourgin, caving with the Spéléo-club de Paris, led the first descent in 1936. Getting down the 120-metre entrance shaft meant rigging a hand winch and bucket — Raymond Gaché and André Bourgin used it to reach the bottom on 29 August 1936. The next breakthrough had to wait until 1969, when the Spéléo Groupe des Hauts-de-Seine cleared the tight S-bend passage and pushed the exploration into the lower reaches of the system.

Can visitors go inside?

A footbridge spans the entrance, so anyone can walk up and look down into the shaft without any caving gear. Actually descending is a different matter entirely — it calls for full vertical caving equipment, experience, and authorisation. This is not a walk-in tourist cave; it's a technical destination reserved for prepared cavers.

What should visitors watch out for?

Rain is the main hazard here: during and after heavy downpours the cave floods fast, and rising water can submerge the entire network of passages. That risk turned real in early November 2022, when two women cavers got trapped underground by rising water. Rescue teams launched an operation on the evening of 9 November 2022, and both were eventually brought out safely.

Frequently asked questions

What does "scialet" mean? It's a Vercors dialect word for a vertical karst sinkhole or pit — a generic regional term, much like "aven" used elsewhere in France, rather than a proper name.

Is the entrance fenced off or protected? A footbridge crosses over the opening, letting visitors safely view the shaft from above without needing to go down.

Do you need permission to descend? Yes — going underground requires proper vertical caving equipment and authorisation. It's a site for trained, equipped speleologists, not for casual solo exploration.

Is the cave dangerous? It can be, particularly during and after rainfall, when water levels rise quickly enough to flood the whole system. Any descent plan needs to account for the weather forecast.

How deep is Scialet de Malaterre? The surveyed system reaches -230 metres, with an estimated total passage length of about 1600 metres, while the entrance pitch itself is 120 metres deep.