Aven des Cèdres

Aven des Cèdres is one of the deepest vertical potholes on the southern flank of Montagne de Lure, in the commune of Saint-Étienne-les-Orgues, Alpes-de-Haute-Provence. This is a destination for caving enthusiasts rather than a show cave with a walkway — reaching the bottom means dropping through a chain of vertical shafts on rope.

What is Aven des Cèdres?

The pothole opens in Bédoulien limestone (a Lower Cretaceous formation) and drops 172 metres, with roughly 250 metres of total passage length. It is the only shaft on Montagne de Lure that passes the 100-metre mark — nearby in the same commune sit the smaller Aven des Bessons (-76 m) and Aven de Ravouest (-47 m), neither of which comes close to its scale.

The discovery goes back to July 1951. A local rural warden, Henri Isnard, pointed out a ventilated pile of stones on the slope to Commandant Brunet and Jean Marty — a telltale sign that air was escaping from a cavity below. On 17 July 1951 the team began clearing the stone pile, opening access to the shaft system. Over the following years, caving groups from Apt and Carpentras carried the exploration forward, later joined by clubs from Fontaine-de-Vaucluse, Grasse and Cannes. In 1954 a joint team finally reached the bottom at -172 m, fixing the depth that still stands today.

How do you get there?

Access follows a forest track — roughly three kilometres separate the parking area from the entrance. The entrance itself is notoriously hard to spot: trip reports describe searching for it well past where it was expected, nearly a hundred metres beyond the anticipated spot. There's no marked trail or signage here — without a precise route (map, GPS point, or contact with a local caving club) it's easy to walk right past the opening.

What will you see inside?

The entrance itself is narrow, but the system opens up considerably beyond it, with a series of pitches and drops linking into a branching network of vertical passages. Two pitches in particular stand out — known as P25 and P27 — both very narrow, with a small stream running through them that catches the light from headlamps and makes the wet rock glow. It's a classic pothole landscape: sheer limestone drops carved by water, and the quiet of a world with no daylight.

Reaching the very bottom means descending the full sequence of pitches using single-rope technique (SRT). Teams that fall short of the lowest chamber typically report needing just ten to fifteen more metres of rope — a reminder of how much precise planning a full descent demands.

When should you go, and who is it for?

Aven des Cèdres isn't a destination for casual visitors. It suits people with real vertical caving experience, ideally accompanied by a local caving club that knows the current state of the fixed rigging (anchors, rebelays) and can judge conditions — particularly water levels after rain, since the narrow, stream-fed pitches can change character fast during heavy weather. The best window for a trip is the dry summer and early-autumn months, when water levels inside the system are low and the forest access track isn't complicated by snow or mud.

The wider area — the southern slope of Montagne de Lure — is worth a visit even for people with no interest in caving: quiet limestone landscapes and a network of hiking trails through the Lure massif. The pothole itself, though, remains a target for a much narrower circle of vertical-caving enthusiasts.

Frequently asked questions

Can you visit Aven des Cèdres without caving experience? No. It's a technical pothole requiring rope equipment and SRT (single-rope technique) skills for both descent and ascent. Entering without training and proper gear is dangerous.

How deep is the cave? Aven des Cèdres drops 172 metres, with around 250 metres of total passage — making it the deepest shaft on Montagne de Lure.

How do you reach the entrance? A roughly three-kilometre forest track connects the nearest parking area to the site. The entrance itself is difficult to locate without precise directions or GPS coordinates.

Who discovered the cave? Rural warden Henri Isnard pointed out the entrance in 1951. Caving clubs from Apt, Carpentras, Fontaine-de-Vaucluse, Grasse and Cannes carried out the exploration, reaching the bottom in 1954.