Bassin turquoise du Trou de la Lune et sa cascade dans la vallée de l'Ibie, coin de baignade en Ardèche

Trou de la Lune: swimming in the Ibie valley (Ardeche)

Turquoise water, limestone rocks, a small waterfall and a wild setting: the Trou de la Lune, in the heart of the Ibie valley, is one of the loveliest swimming spots in southern Ardeche. Just 25 minutes from Mas Saint Antoine, it is the perfect outing for an afternoon by the water, far from the crowds. After ten years advising our guests, here is our complete guide: the valley and its history, the swimming spots, access, and our tips to enjoy it safely.

What are the Trou de la Lune and the Ibie valley?

The Trou de la Lune is a natural pool of clear water, fed by a small waterfall, tucked into the Ibie valley. It is the best-known swimming spot in this wild valley, between Vallon-Pont-d’Arc and Saint-Maurice-d’Ibie.

The Ibie valley, the little Ardeche

The Ibie is a tributary of the Ardeche that carved its bed into the Gras plateau over some thirty kilometres. This valley is often nicknamed the little Ardeche for its unspoilt beauty and peaceful character. You cross vineyards and lavender fields, and discover the hamlet of Les Salelles with its stone houses, or the Arche du Ranc de l’Arc, a geological curiosity.

The Trou de la Lune: a waterfall with a mill’s past

A little-known detail: the Trou de la Lune waterfall is not entirely natural. It is in fact the remains of an old dam that once fed the Noe mill. Today, the small fall and its pool, facing a submersible bridge, form a postcard scene with the translucent water typical of Ardeche’s limestone rivers.

The legend of the treasure

The place has its legend. It is said that every hundred years, when the moon passes behind the hole, a ray lights up a rock hiding a fabulous treasure: two cauldrons full of gold coins. But beware the witch who, so the story goes, turns to stone anyone who dares come back for it. Plenty to fuel children’s imagination along the way.

How to reach the Trou de la Lune from Mas Saint Antoine?

The Trou de la Lune is about a 25-minute drive from Mas Saint Antoine: ideal for a half-day escape. One important point, however, about parking.

From Approx. driving time
Mas Saint Antoine (Bourg-Saint-Andeol) 25 min
Vallon-Pont-d’Arc ≈ 15 min
Montelimar / A7 motorway ≈ 45 min
Avignon TGV station ≈ 1 h 05

Where to park? (the thing to know before you go)

The immediate surroundings of the bridge are private property: parking is forbidden there, and the area is a protected natural site home to protected species. The right move: park in the village of Lagorce or in Vallon-Pont-d’Arc, then reach the site on foot or by bike. It is also far more pleasant for taking in the valley along the way.

Where to swim in the Ibie valley?

Swimming is the main activity here, and the Trou de la Lune is the jewel.

The Trou de la Lune pool

Its water, a lovely turquoise, was rated good quality in the latest season. The pool alternates shallow areas, perfect for paddling with children, and deeper basins loved by swimmers. White rocks and limestone walls frame it all in a luminous setting.

Other quieter spots

As the Trou de la Lune is the most popular spot, it can get busy in peak season. The good news: walking up or down the Ibie, you will find other quieter basins and pools, especially in the morning. A chance to turn your swim into a lovely riverside walk.

Criterion Detail
Type River swimming (unsupervised)
Water Turquoise, rated good quality (2025)
Depth Shallow areas + deeper basins
Access Free, on foot from Lagorce or Vallon

An honest heads-up: the Ibie is a capricious river. Some years, in high summer, the level drops sharply and parts can dry up. Spring and early summer generally offer the best water. If in doubt, check before setting off.

Is the swimming supervised? Our safety tips

No, this is wild, unsupervised river swimming: it is up to you to adopt the right habits to enjoy it safely.

  • Watch children at all times, especially near the deeper basins.
  • Never dive without checking the depth: it varies a lot with the spot and the river level.
  • Water shoes are strongly advised: the bottom is rocky and sometimes slippery.
  • After rain, the river can rise quickly: stay careful.
  • Bring drinking water and shade, and take all your litter home: the site is protected.

What else can you do in the Ibie valley?

  1. Hiking and cycling: trails and quiet lanes run along the Ibie, between vineyards, lavender and scrubland.
  2. The hamlet of Les Salelles: a charming cluster of stone houses, ideal for a heritage break.
  3. The Arche du Ranc de l’Arc: a natural arch shaped by water and time on the Gras plateau.
  4. Canoeing: a few minutes away, the neighbouring Ardeche river is perfect for canoe trips.

When to visit the Trou de la Lune?

Spring

Often the finest time: the river runs well, the water is clear and the site still quiet. Ideal for a first visit.

Summer

The Trou de la Lune is very popular in July and August, sometimes crowded at midday. Come early in the morning for cool air and calm, then head back to the Mas pool in the afternoon.

Autumn

In September, the site regains its calm and gentleness. It is also when Mas Saint Antoine is happily booked exclusively for groups and retreats.

Winter

Skip the swim, but the valley is perfect for beautiful winter walks in absolute quiet.

What equipment and budget should you plan?

Great news: access to the Trou de la Lune is completely free. There is no ticket office and no opening hours. The only real essential is good wild-swimming gear.

Criterion Detail
Price Free access
Water shoes Strongly advised
Water and shade Bring your own (few shops)
Parking Lagorce or Vallon, then on foot

What mistakes should you avoid?

  1. Parking by the bridge: it is private and forbidden. Park in Lagorce or Vallon and finish on foot.
  2. Coming at midday in August: the busiest time. Prefer the morning or the autumn.
  3. Forgetting water shoes: rocky, slippery bottoms quickly spoil barefoot swimming.
  4. Diving without checking the depth: it changes with the spot and the water level.
  5. Leaving litter: the site is listed and fragile. Take everything home.

How to combine the Trou de la Lune with other visits?

Day 1 – Swimming and major sites

Morning: a swim at the Trou de la Lune. Afternoon: head to the nearby Pont d’Arc and Chauvet 2 Cave, before returning to the Mas for the pool.

Day 2 – Along the valley

Spend the day in the Ibie valley and its villages, then enjoy our panoramic terrace at sunset. To plan your outings, browse The Mas Magazine and settle into one of our 6 cottages as a base camp.

Why stay at Mas Saint Antoine to discover the Trou de la Lune?

  • ✅ 25 minutes from the Trou de la Lune and the Ibie valley.
  • ✅ 6 independent cottages, on 2 hectares of enclosed, wooded grounds.
  • ✅ A 13×6 m saltwater pool to extend the freshness on your return.
  • ✅ Air-conditioned cottages, rated 4.9/5 from over 130 verified reviews.
  • ✅ Estate selected by Petit Fute 2026.
  • ✅ Exclusive hire for up to 38 people: perfect for a nature weekend, a family gathering or an off-season retreat.

Check availability at Mas Saint Antoine

In conclusion

  1. The Trou de la Lune is the finest swimming spot in the Ibie valley, 25 minutes from the Mas.
  2. Its waterfall is actually the legacy of an old mill; its treasure legend adds to the charm.
  3. Park in Lagorce or Vallon, never by the bridge (private), then walk to the site.
  4. Unsupervised swimming: water shoes, caution, and respect for this protected site.
  5. Spring and autumn are the best times; in summer, come early in the morning.

Some places seem to suspend time: the Trou de la Lune, with its turquoise water and its waterfall born of an old mill, is one of them. From the Mas, this little paradise is just fifteen minutes and a few more away. See you soon in Ardeche.

Overview of the Mas Saint Antoine estate, its cottages and grounds in Bourg-Saint-Andeol, southern Ardeche

Plan your stay in Ardeche

25 minutes from the Trou de la Lune, Mas Saint Antoine welcomes you: 6 independent cottages, a 13×6 m saltwater pool and large enclosed grounds. The ideal base to explore southern Ardeche and Drome Provencale.

Check availability

Have a question? Call Helene on +33 6 29 11 41 88

Frequently asked questions

Where is the Trou de la Lune located?

The Trou de la Lune is in the Ibie valley, in southern Ardeche, in the Lagorce area between Vallon-Pont-d’Arc and Saint-Maurice-d’Ibie. It is a natural swimming pool fed by a small waterfall. You reach the site on foot or by bike from Lagorce or Vallon, as the surroundings of the bridge are private.

How far is the Trou de la Lune from Mas Saint Antoine?

The Trou de la Lune is about a 25-minute drive from Mas Saint Antoine in Bourg-Saint-Andeol. It is ideal for a half-day out: swimming and a walk in the Ibie valley in the morning, then back to the estate in the afternoon for the saltwater pool and the terrace.

Is swimming allowed at the Trou de la Lune?

Yes, swimming is allowed and is the main activity. It is, however, wild, unsupervised river swimming. The turquoise water was rated good quality in the latest season. Bring water shoes and watch children, especially near the deeper basins.

Where can you park to reach the Trou de la Lune?

The immediate surroundings of the bridge are private property where parking is forbidden, within a protected natural area. You must park in the village of Lagorce or in Vallon-Pont-d’Arc, then reach the Trou de la Lune on foot or by bike. It respects the site and is far more pleasant for discovering the valley.

What is the best season for the Trou de la Lune?

Spring and early summer are often the best times: the river runs well and the site is still quiet. In July and August it is very busy, so come early in the morning. Autumn, in September, regains calm and gentleness, and it is also when Mas Saint Antoine is booked exclusively for groups.

Can the Trou de la Lune run dry?

Yes, the Ibie has an irregular flow. Some years, in high summer, the level drops a lot and the site can be partly dry. The best water is usually in spring and early summer. If in doubt before travelling, check current conditions with the local tourist office.

Where does the Trou de la Lune waterfall come from?

Contrary to what is often believed, the Trou de la Lune waterfall is not entirely natural: it corresponds to the remains of an old dam that fed the Noe mill. This small fall, facing a submersible bridge, gives the pool its distinctive charm today, between stone and turquoise water.

Are there other swimming spots in the Ibie valley?

Yes. The Trou de la Lune is the best-known pool, but walking up or down the Ibie you will find other quieter basins and pools, especially in the morning. Swimming then becomes a lovely riverside walk, between limestone rocks and Mediterranean vegetation.

Is the Trou de la Lune suitable for children?

Yes, the pool has shallow areas perfect for paddling as a family. Stay vigilant, though, as there are also deeper basins and the site is unsupervised. Water shoes protect little feet on the rocky bottom, and a bit of shade is welcome during the hottest hours.

What else is there to do around the Trou de la Lune?

The Ibie valley invites hiking and cycling between vineyards and lavender, and the discovery of the stone hamlet of Les Salelles and the Arche du Ranc de l’Arc. The site is very close to Vallon-Pont-d’Arc, the Pont d’Arc and the Chauvet 2 Cave, and the neighbouring Ardeche river is perfect for canoe trips.

Article written by Bernard Favre, owner of Mas Saint Antoine.


Published on :22 July 2026  -  Filed under: Sport and Adventure  -  Tagged : , , , , ,