Magical, mysterious, atypical… the underground world has a number of unique characteristics, unmatched by any other outdoor activity. Caving is adventure with a capital A!

Whether you’re a novice or a seasoned rider, the Plateau des Petites Roches opens the door to a fascinating universe that has nothing in common with the outside world. For it is here that a world-famous through-and-through mountain invites you on a timeless journey, on the scale of the Earth and its formation. Name? La Dent de Crolles.

The Dent de Crolles

Culminating at an altitude of 2062 metres, the Dent de Crolles is the terminal spur of the Chartreuse massif. Like an age-old guardian, it dominates the valley, recognizable by its distinctive shape from other, more distant mountain ranges. It also watches over the Plateau des Petites Roches, of which it is one of the most visible and authentic symbols. For hikers, it remains a favourite destination, making it the most popular summit in the Isère department.

Its most striking feature, however, is its underground network: 70 kilometers of galleries and shafts, as well as 11 major entrances, discovered little by little over the last century and right up to the present day by successive generations of speleologists. This unimaginable underground labyrinth is one of France’s largest natural underground networks, and has long since made the Dent de Crolles famous beyond its borders.

The sheer size of the network, the result of millions of years of erosion and corrosion by water on the rock, offers almost unlimited possibilities for exploring the mountain: from “Discovery” outings to the “Adventure” tour. Trou du Glaz or the Grotte Chevalierto the “Traversées” – including the famous Glaz-Annette crossingfirst produced in 1947. Because yes! The Dent de Crolles can be crossed! Imagine entering on one side of the mountain and exiting on the other. A day of unforgettable adventure with family and friends.

Caving at the Dent de Crolles,

with a professional guide

Although caving is a marvellous activity, attractive and accessible to as many people as possible, it is by nature practised in a hostile environment where risks exist. This is particularly true inside the Dent de Crolles, where the complexity of the network means that the main danger is undoubtedly getting lost. So it's essential to be accompanied on an underground expedition by a recognised professional who has a thorough knowledge of the routes and can handle all the logistical, technical and organisational aspects involved in a successful underground foray. So if you'd like to discover the Dent de Crolles from the inside, and offer a wide range of caving trips to suit all levels, ages, interests and budgets.

Where to go caving on the Plateau des Petites Roches?