A former military building, Fort l’Écluse is the venue for a wide range of activities: via ferrata, concerts, exhibitions, walks… Why not spend a day there with your family to discover all its secrets?
Every year, it closes for a few months to give itself a facelift. A great opportunity to pay it another visit.
But before we unveil our tailor-made programme, a little history for those who don’t know this giant built in rock.
Fort l’Écluse in brief
Fort l’Écluse is a military structure in Léaz. It is thought to have been built from the ruins of the old fortified castle founded between 1225 and 1277.
In terms of construction, since the 17th/18th centuries the lower fort has consisted of an enclosure reinforced by a round tower, the Porte de France, and a parade ground leading to another entrance, the Porte de Genève. For your information, the most beautiful entrance is the Porte de France. No, no, we’re not chauvinists here 😉
The terrace at the top of the Porte de France offers an exceptional view of the Rhône. The buildings of the upper fort were built in the middle of the 19th century, high up to protect the fort from possible attacks from the mountains. The two forts are linked by 1,165 steps cut into the rock. Several artillery casemates and terrace batteries complete the complex.
Let’s start the day with… a guided tour
Words are all very well, but discovering it and walking through it yourself is even better. That’s why we’re offering you the chance to visit Fort l’Ecluse through the eyes of Jean-Dominique, who is in charge of the guided tours. We recommend a morning visit so that you can enjoy the other activities at the fort in the afternoon.
For 1 hour, this guide will explain all the secrets of this mysterious fort. He will take you through its battles, past failures and life within its walls. You’ll discover that the Fort has belonged to different owners and that it has often lost its battles, hence its nickname of “the most useless fort in France”.
But despite this, we guarantee you’ll become attached to this giant of stone who has been abandoned time and time again… Did our teaser leave you wanting to know more?
Practical information: Guided tours are available every Friday, Saturday and Monday at 11am, 1pm, 2.30pm and 4pm. And what’s more, they’re free.
Are you ready to travel back in time?
We continue with… the fort’s exhibitions
Take a guided tour of the famous casemates, where a number of exhibitions have been set up. Nature, culture and contemporary art await you. If some of the exhibits have intrigued you, here’s a quick overview of the exhibitions before you go:
- At the heart of the storm: through photos and lightning objects, discover this electrical phenomenon in a fun and entertaining way.
- Lesser rhinolophids: enter the world and intimacy of these small bats living in the upper fort.
- At the heart of the Cluse: take an immersive tour of the fort’s history, using models and photos.
Which exhibition are you most looking forward to seeing?
History digs a hole! Time for lunch
We suggest you get back in the car and head for the Pont Carnot road in Collonges (just a few minutes from Fort l’Ecluse) to eat at the “P’tite Quinette” food truck. You’ll find a guinguette atmosphere and the home-made burgers are delicious. Special mention for the vegetarian burger. A real treat!
Afternoon adventure!
Not afraid of heights? That’s just as well, because the activity we’re about to introduce you to is not available on land! Suspense… It’s the adventure course in the upper fort: the Fort l’Ecluse adventure. After warming up by climbing the 1165 steps (because you do have to climb them to take part in this activity), all you have to do is get your equipment. Balance games, Tarzan jumps, monkey bridges, tyrolean traverses…
Another thrilling activity is the via ferrata, a self-guided route for the more experienced. After a short walk, you will reach the limestone wall that separates the lower fort from the upper fort. Although relatively accessible, this via ferrata is not recommended for beginners. You can hire your equipment from Fort L’Ecluse Aventure free of charge. An exceptional view of the Rhône and the Ecluse gorge awaits you!
Practical information:
Altitude: 430 / 530 m
Difference in altitude: 150 m
Length of route: 400 m
Walking time: 1h30
Difficulty: AD
Walks from Fort l’Écluse
You’re not into thrills and spills, but you’re more into beautiful panoramas? There are several walks available from the Fort during its opening period (1 April to 30 November).
Take Fort l’Ecluse on the banks of the Rhône. With its 12km and 720m ascent, this hike will give you a magical view of the Rhône Cluse, the Vuache and the Etournel.
You can also go as far as the Léaz belvedere and admire the breathtaking panorama over the Rhône valley on a 10km loop hike with a 600m ascent.
When the music resonates in Fort l’Ecluse
Jazz…
Fort l’Ecluse is not just a place of history! It’s also a musical stage for jazz lovers. For over 10 years now, this musical genre has been making its way into the fort, offering visitors exceptional concerts throughout the summer and at nightfall during the Jazz in Fort L’Ecluse festival. With concerts by internationally renowned artists, let yourself be enchanted by the notes of jazz in the heart of an exceptional site. Outside the summer season, several Jazz in Fort L’Ecluse concerts are held in the orangery of the Château de Voltaire.
One thing’s for sure: this experience will not leave you indifferent!
Admission is free and shuttle buses are available from Collonges-Fort l’Ecluse.
Check out the dates for the next edition now!
And now electro!
After two successful editions with just over 1,000 festival-goers,ElectroFort Festival is back on 27 September 2025. This electro festival brings together internationally renowned and established DJs from France and Switzerland. Places are limited.
When jazz and electro aren’t playing, it’s the walls that are doing the talking. Every Wednesday and Sunday in July and every Wednesday and Friday in August, relive the history of the Fort through a fascinating sound and light show.
We warned you: you can spend a whole day at the Fort, combining sport and culture. A great idea for a day out with your children!
How to get to the Fort?
There are several ways to get to Fort L’Ecluse:
- By car, take the D884 from Geneva (about 35 minutes), the A40 from Lyon (about 1 hour 20 minutes’ drive) or the A6 from Paris. On-site parking is available for around 60 cars;
- By train, to Léaz Longeray station. This is about a 10-minute walk from the Fort.
Would you like more information about Fort L’Ecluse? Come and meet us at one of our tourist information offices– we’ll be delighted to help!
Thematics
