Some hikes stay with you forever, and the Ars waterfall is one of them. Above Aulus-les-Bains, in the Couserans, the water from the Guzet plateau plunges 246 metres in three successive tiers — the middle tier fanning out into a veil some sixty metres wide. At snowmelt you hear the roar long before you see the falls, and the mist of spray cools the woods: locals fondly call it the natural "mist machine" of the Pyrenees. Here is how to plan this emblematic Ariège hike.
The Ars waterfall in numbers
- Total height: a 246-metre drop, in three successive tiers.
- Width: the middle tier spreads over roughly 60 metres.
- Classic loop: about 10.5 km, +830 m of climbing, 4.5 to 5.5 hours of walking.
- Start: Aulus-les-Bains (spa village in the Couserans, Garbet valley).
- Difficulty: moderate — fine for regular walkers, sporty for children.
- Peak flow: May and June, at snowmelt.
The classic route: the loop from Aulus-les-Bains
The most complete circuit is a loop of about 10.5 km with 830 metres of ascent; allow 5 hours of actual walking. Park at the small hairpin car park on the edge of Aulus-les-Bains, on the road to the Col de Latrape. The climb follows the GR10 through a beautiful beech and fir forest, in steady switchbacks, up to the foot of the falls — arriving in front of the veil of water is a magic moment. The return runs down the opposite side past the more secretive Fouillet waterfall, a second reward before dropping back to the village.
If you prefer something simpler, the direct out-and-back along the GR10 to the foot of the falls shortens the day while keeping the essential spectacle. The keenest walkers can push on towards the plateau and the Guzet lakes, but the classic loop is more than enough to fill a memorable day.
When to go? May-June for the big show
The Ars waterfall is at its peak in May and June, when snowmelt swells the flow: it is the most impressive period, but also the trickiest — the trail can stay snowy or slippery early in the season, especially between the waterfall and the footbridge. Wait until the snow has completely gone before attempting the loop. In July-August the flow is tamer but the hike remains magnificent, with the bonus of a dry trail and a cool forest in a heatwave. Autumn brings superb colours and quiet.
With children? Yes, but prepared
The full loop is demanding for young legs: 830 metres of climbing is a proper mountain day. Children used to walking (from around 8-10 years old) manage it very well, especially with two waterfalls as the promise. With younger ones, choose the out-and-back along the GR10 towards the foot of the falls, turning around whenever tiredness sets in. The trail is well made but remains a mountain path: no pushchairs, even all-terrain ones.
Gear and safety
- Hiking boots with good tread — the surrounds of the falls are wet and slippery.
- Windproof or light jacket: the spray soaks you quickly at the foot of the falls, even in summer.
- Water and a picnic: no refreshment point on the loop.
- Poles are welcome for the descent via the Fouillet.
- Check the weather before setting off: storms and balcony trails do not mix.
Getting there from Domaine de la Trille
From Domaine de la Trille in Sainte-Foi, allow about 1 h 45 of driving to reach Aulus-les-Bains, via Foix and then the Couserans valley — a scenic route that can be combined with the Étang de Lers and the Port de Lers to make one of the finest day trips in the Ariège Pyrenees. Leave early, pack a picnic, and keep the evening for unwinding on the terrace of your gîte or caravan.
