Grotte de la Cheminée

Grotte de la Cheminée is one of the most distinctive caves of the Vercors massif, tucked into the forest on the Herbouilly plateau in the commune of Saint-Martin-en-Vercors, in France's Drôme department. Its name — the "chimney cave" — comes straight from what greets visitors at the entrance: the ceiling is pierced by a round natural shaft, a scialet, that lets daylight pour in and shapes the opening into a striking rock arch.

Where exactly is the cave?

The entrance sits at roughly 1,360 metres of altitude, on the edge of the Herbouilly clearing, across the road that links Saint-Martin-en-Vercors to Saint-Julien-en-Vercors. The spot lies almost where the territories of three communes meet — Saint-Martin-en-Vercors, Saint-Julien-en-Vercors and Villard-de-Lans — deep in the forested plateau. Drivers can reach it either from Villard-de-Lans via the Bois Barbu road, or directly along the road connecting Saint-Martin and Saint-Julien-en-Vercors. A roadside sign marks the spot, with parking close by.

What does the inside look like?

Getting down into the cave means picking a way across a jumble of fallen rock, lit from above through the chimney-like opening. Further in, the walls carry stalactites, stalagmites and small gours (rimstone pools), and the route ends at a temporary underground lake, fed by rain and melting snow funnelling down through the shaft. In dry spells the lake can shrink to almost nothing, so it looks its best in spring or after rain.

How do you get there, and how long does a visit take?

A well-kept path leads from the parking area to the cave mouth — about 200 metres, a ten-minute walk. Exploring the inside takes roughly an hour. The descent reaches about 90 metres below the surface, but no climbing gear is needed: visitors stay on their feet the whole way, though the ground turns steep and slippery over the boulder field, so sturdy footwear matters. Proper lighting is essential — a helmet with a headlamp (plus a spare) and a strong torch, since the final chamber is large and completely dark.

Where does the name come from, and who explored it first?

Jean Delmas was the first to survey the cave, in 1893. A fuller exploration followed on 25 May 1900, carried out by a four-man team: Decombaz, Pellerin, Bouzigues and Deya. The cave's name shifted over the years — it was first known as the "grotte des fées" (fairies' cave), then "grotte d'Herbouilly," before settling on the name that describes its trademark shaft.

Are there traces of earlier visitors?

Numerous deer antlers have turned up inside the cave, and some show signs of working dating back to the Neolithic period — evidence that people were coming here long before recorded history. It isn't set up as an archaeological site to visit as such; the finds simply came to light during cave exploration.

FAQ

Is the visit difficult? No climbing or ropework is required — you walk the whole route on foot — but the descent over the boulder field is steep and slippery, so care and solid footwear are needed.

Is entry free? Yes, there's no admission fee and no supervision on site, so visitors explore at their own risk.

What should you bring? A helmet, a headlamp with backup power, and an extra strong torch — the lower chamber is pitch dark.

When is the best time to visit? The cave can be visited year-round, but the temporary lake at the bottom is most impressive in spring or after rainfall, and nearly disappears during long dry spells.

How do you get there? The easiest approach is from Villard-de-Lans via the Bois Barbu road, or along the road between Saint-Martin-en-Vercors and Saint-Julien-en-Vercors — there's a roadside sign and parking, followed by a short, well-marked path to the entrance.