Northing: 45.30669° Easting: 5.85468° Altitude: 1,670 m
How to find it
Grotte Chevalier is located under the south nose of Dent de Crolles. From the Col du Coq follow the waymarked GR9 up the zigzags above the Col des Ayes. At the top of the zigzags the GR9 goes off to the left towards Trou du Glaz. Follow the right hand path up towards the Pas de l'Œille and when it starts an ascending traverse to the right look for a thin line going off beneath it. This becomes a more distinct path as it follows a line between the cliffs above and the steep valley below. Continue round the nose, and traverse on shale ledges for a couple of hundred metres. There may be fixed ropes for protection. Grotte Chevalier is an alcove 30 metres or so above the traverse, and is accessed by a thin ascending path through the loose scree and vegetation. Once at the right level, Grotte Chevalier is on the right under the cliff fronted by an unstable scree slope.
Although Grotte Chevalier was first explored in 1943, it wasn't connected to the main system until 1984 - and that was from passages climbed into from above P36, now more easily accessed from Gouffre Bob Vouay. The voie normale which branches off from Galerie 43 on the Trou du Glaz - Grotte Annette Bouchacourt traverse, was explored in the same year. Both routes enter via a sequence of pitches, and it is not possible to go the other way unless the route has been pre-rigged. Grotte Chevalier, however, is worth exploring in its own right and can be combined with a visit into Grotte Annette Bouchacourt. Basically one enormous passage with a main side passage leading up to the as yet unconnected Grotte Petzl, it penetrates the heart of the mountain for about a kilometre, and a depth of about 150 m. There is an unstable scree slope just inside the entrance, which may require some excavation, although Maxi Méga Marmotte provides an alternative exit - see note above.
The standard route from Trou du Glaz enters down Puits de la Toussaint close to the end. This is a superb trip featuring the magnificent 55 m Puits Maurice, and a tensioned traverse around the top of Puits de l'Oubliette. All the pitch heads are well-equipped with belay rings and traverse lines. The traverse is described here in French, and a loose translation by the author is available here (use at your own risk). The route descending from Gouffre Bob Vouay joins the standard route at the top of Puits Maurice.