Caving in the Grotte des Forges, an underground river
Caving in the Grotte des Forges, on the shores of Lake Vouglans
Exploration of an underground river at Lake Vouglans in the Jura
Practical information – Grosdar Canyoning
Duration
Half a day
(± 3 hours)
Level
Beginner – suitable for athletes
Price
€64.00 per person
Minimum age
Ages 10 and over
Location
Moirans en Montagne, Jura, Franche-Comté

What to expect on your caving trip to Grotte des Forges
After a short walk to the entrance, discover caving at the Grotte des Forges on the shores of Lake Vouglans, in the Jura region of Franche-Comté. This fun half-day exploration of an underground river immerses you in a fascinating world of swimming and geological discoveries, with explanations of how the caves in the Jura massif were formed.
As you make your way through, explore a vast underwater gallery by swimming through cool, crystal-clear water. A unique opportunity to go for a swim underground.
Ideal for a first experience of cave diving, the Grotte des Forges is one of the most beautiful caves in the Jura.
An underground river perfect for discovering caving in the Jura
This caving trip near Lake Vouglans is perfect for a half-day outing with the family – children aged 10 and over are welcome – or with friends. A refreshing and fun experience in a little-known and unspoilt part of the Jura.
Book your caving trip at the Grotte des Forges in Moirans-en-Montagne
Book your caving trip in the underground river at the Grotte des Forges today. Enjoy a unique half-day out with your family – children aged 10 and over are welcome – or with friends, on the shores of Lake Vouglans!
An introduction to cave diving at the Grotte des Forges, on the shores of Lake Vouglans
A unique underground river in Franche-Comté, deep within the Jura mountains.
Why choose caving in the Grotte des Forges?
- Suitable for everyone, from beginners to experienced athletes, aged 10 and over.
- Fun and not too technical, ideal for families, with children and teenagers, or with friends.
- An educational exploration of an underground river.
- Cool temperatures even during the heatwave.
Safety, supervision and equipment
Being able to swim is essential!
Caving trips to the Grotte des Forges in Moirans-en-Montagne, on the shores of Lake Vouglans in the Jura, are suitable for beginners and experienced cavers aged 10 and over. This half-day excursion explores an underground river in Franche-Comté.
The Grotte des Forges is located in the immediate vicinity of Saint-Claude, the resort of Les Rousses, Lake Vouglans and Clairvaux-les-Lacs. The journey from Geneva, Lausanne, the Pays de Gex, Lyon or Dijon takes between 1½ and 2 hours by car.
What to bring
- Swimsuit,
- Sports shoes (trainers or hiking boots) – Available for hire,
- Water bottle,
- Snacks,
- A waterproof camera or a GoPro.
The price includes:
- Supervision by a state-qualified guide,
- Team and individual equipment,
- The guide’s third-party liability insurance.
Book a private event for a stag or hen party
If you’re organising a stag or hen party, our group packages allow you to book a private guide to explore the Grotte des Forges.
Frequently Asked Questions – FAQ
Is the Grotte des Forges suitable for children?
Yes, caving at the Grotte des Forges is suitable for children aged 10 and over.
Is it compulsory to know how to swim?
Yes! There are sections where you’ll need to swim. If you can’t swim, we can suggest other caving trips.
I’m not very sporty – can I still take part?
Yes, the Grotte des Forges is suitable for those who are not particularly fit. However, you must be able to walk and swim in the mountains for three hours. Of all our caving trips in the Jura, this is one of the most accessible. If you cannot swim, try exploring the Grotte de la Pontoise instead.
I’m very sporty – will I get bored?
No, the Grotte des Forges is magnificent and has something for everyone. However, if you’re looking for a caving trip with more rope work and abseiling, you can explore the Grotte de Coinans.
How long should I allow for this?
Allow 3 hours for the activity.
Where is the Forges caving centre located?
The Grotte des Forges is located in Moirans-en-Montagne, on the shores of Lake Vouglans, in the Jura. It is a 30-minute drive from Clairvaux-les-Lacs and Saint-Claude. Allow an hour’s drive from Les Rousses, Geneva or the Pays de Gex.
I wear glasses – can I take part?
Of course! Make sure you bring a cord. Your guide will explain how to keep them from getting lost or damaged. Ideally, bring an old pair. Better still, wear contact lenses if you can.
What if the weather is bad?
The guide may change the itinerary. If the activity cannot go ahead, we will reschedule it for another day. If this is not possible, we will cancel it. In that case, you will receive a full refund.
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