Groin Canyon: the guide to the cave canyon (Bugey)

Caves, siphons, long swims in the dark and spectacular jumps: the Groin canyon, in the Bugey, is one of the most astonishing in France. This semi-underground canyon, about an hour from Annecy, offers an out-of-the-ordinary adventure, halfway between canyoning and cave exploration. Here's the complete guide to this one-of-a-kind route.

1. Where is the Groin canyon?

The Groin canyon is in the Bugey, in the Ain, about an hour's drive from Annecy. It's the farthest of our canyons, but also one of the most memorable: it's well worth the trip for its utterly unique atmosphere.

Far from the buzz of the lake, you enter a world apart, where water has carved the rock to form a partly underground route. An experience that's completely off the beaten track.

2. A unique cave canyon

What makes the Groin exceptional is its cave (troglodyte) character: much of the descent takes place inside the rock, in galleries and caves carved by the river. It's one of the few canyons of this kind in France.

You progress on the border between canyoning and aquatic caving: headlamp on the helmet, you swim in the half-light, cross siphons and emerge into pools lit by a shaft of daylight. A mysterious, grand atmosphere that stays with you.

3. The route: caves, siphons and jumps

The Groin canyon combines every ingredient of adventure:

• Caves and galleries where you move by headlamp;
• Siphons and half-submerged passages that spice up the descent;
• Long swims in clear water, in the half-light;
• Jumps of up to 12 metres, always optional, into deep pools.

This mix of darkness, swimming and committing jumps makes the Groin a powerful trip, reserved for those seeking a different kind of experience.

4. Who is it for? Level and age

The Groin canyon is a sporty, committing trip that requires being perfectly comfortable in the water and unafraid of confined spaces and darkness. It's done from age 14, with a good level of fitness.

It's clearly not a beginner's canyon: if you're starting out, begin with the Discovery trip in the Angon canyon (from age 8). The Groin makes a superb goal once you've gained experience.

5. When to do the Groin canyon?

The season runs from spring to autumn, but the Groin is particularly sensitive to flow: too much water, and some underground passages become impassable. That's why the date must be chosen with the guide, who checks conditions to ensure a safe, enjoyable descent.

6. How a trip works

After the drive to the Bugey and kitting up (reinforced wetsuit, helmet with lamp, harness provided), the guide gives a detailed briefing — the underground section calls for extra care. You then enter the canyon to alternate swims in the caves, siphons, jumps and headlamp passages. Allow a full day including travel.

7. Descending the Groin with a guide

Given its underground, committing nature, the Groin canyon must be descended with a professional who knows every gallery and siphon. Our state-certified guides secure the whole route so you can live this unique adventure in full confidence — guiding that's regularly praised in our reviews, with a 5.0/5 rating on Google. Find all our canyons in the guide to the canyons of Annecy.