In 1960, Fort de Caluire acquired a new life as an underground mushroom farm. If this sounds as wonderfully random to you as it did to me, you might be interested in knowing that France, in fact, has a long tradition of repurposing disused subterranean spaces as mushroom farms.

Fort de Caluire

Last year, I wrote about my New Year’s Day visit to Fort Loyasse, an abandoned 19th century fort in the Vaise district of Lyon and one of the city’s most popular urban exploration sites. One year later, on one of the last days of 2015, Paul and I had the opportunity to visit another structure belonging to the first defensive belt of Lyon: Fort de Caluire, or Champignonnière de Caluire.

The first defensive belt of Lyon

The first defensive belt of Lyon consists of over 20 forts, bastions and other military structures in and around Lyon built between the 1830s and 1840s as protection against Austria’s military power. Although they share the same origin story, there are huge differences in how the structures have fared through time.

Out of the over 20 structures, many have been demolished. Fort Loyasse is still standing, though heavily damaged by decades of neglect and vandalism. Fort Saint-Jean, perhaps the most well-known of the bunch, is in active use by the Veterinary Service of the Armed Forces. The aboveground structures of Fort de Caluire have been destroyed, but the underground complex remains in excellent condition – and strictly off-limits to the public.

Fort de Caluire

Guardians of Fort de Caluire

In fact, the only way to visit Fort de Caluire is to book a private guided tour through a small local association called OCRA-Lyon. Now, a sworn independent traveler may experience heart palpitations at the mere thought of a “guided tour”, but let me assure you that this one is nothing like visiting any ol’ heritage site, prepackaged and prettified for public consumption.

The fort comes with no information signs, bright lights or ice cream stands. It’s a dark and rugged place, and if you don’t watch your step, you can easily trip over a rusty rail or invisible manhole on the ground. Bringing a good torch is necessary.

Moreover, the members of OCRA-Lyon are some of the most dedicated ruin fans you’ll ever meet, sporting delightful pseudonyms such as Le troll ki pète (”Farting Troll”) and Tétard le fétard (”Party Tadpole”). On a mandate from the City of Lyon, they act as the guardians of the fort, working to preserve it in its original state. By paying the nominal 5 euro fee you will support the fort’s continued existence.

To us, this sounded like the perfect way to spend the last Wednesday morning of 2015. After a short email exchange with OCRA-Lyon our appointment was set.

Fort de Caluire

The meeting

A low stone building with discreet metal doors in the Caluire-et-Cuire suburb of Lyon, the fort, in its present form, would not have been easy to recognize as a fort unless you knew what it was.

We arrived at the parking lot facing the fort feeling a little sluggish from the overcast weather and the excessive, if delicious, Christmas food we’d been eating non-stop for the past week. My mood quickly changed, though, as we were met with Alain and Jonathan (no pseudonyms available), our tour guides for the following hour.

Fort de Caluire

The guys, though very friendly and passionate about the fort, spoke only little English, and I spoke no French at all, so Paul helped translate the conversation. We introduced ourselves and had a little chat before Alain proceeded to summon the key to the fort and open the heavy doors.

What lay behind was a dim, sloping tunnel, illuminated by small LED lights only. We turned on our torches and started the descent.

Fort de Caluire

Down under

Before long, the tunnel opened into a caponier: a large open space and the control room of the fort’s operations. The caponier had entrances to six smaller rooms, each with one opening in the thick stone wall for cannon fire, one for letting out exhaust fumes and two for rapid fire.

To our left and right, two more tunnels extended further into the darkness than the eye could see. These were shooting galleries with several small openings for rapid fire. A pair of rusty rails, built for moving equipment inside the fort, ran the length of the other tunnel.

The caponier had been illuminated just enough to allow for some photography, but deep inside the shooting galleries we were at the mercy of our torches. For what was technically a guided tour this felt an awfully lot like urban exploration proper.

Fort de Caluire

The rise of Champignonnière de Caluire

The first defensive belt of Lyon, as I wrote in my post about Fort Loyasse, was never used for its intended purpose. After the attack from Austria never came, Fort de Caluire, too, was unceremoniously abandoned in 1900. But this didn’t mean that it’s story was over.

In 1960, after 60 years of abandonment, the fort acquired a new life as an underground mushroom farm. If this sounds as wonderfully random to you as it did to me, you might be interested in knowing that France, in fact, has a long tradition of repurposing disused subterranean spaces as mushroom farms.

It is the constant humidity, moistness and darkness of these spaces that makes them ideal for the delicate art of mushroom farming. The traditional center of the trade, of course, is Paris, where over 300 underground champignonnières were estimated to operate in 1880. Champignonnière de Caluire was one of the dozens, if not hundreds, farms around the country.

Fort de Caluire

The present

Despite its legendary status, the subterranean mushroom farming scene began to wane towards the end of the 20th century as cheap mass-produced mushrooms took over France’s food market. Today almost all of the farms have disappeared, and those few still left are struggling to make ends meet.

Champignonnière de Caluire had closed down already in 1972, after only 12 years of operation. It is only through the sustained efforts of OCRA-Lyon that the underground complex continues to thrive in the present day while others of its kind are perishing.

So if you’re ever in Lyon and looking for a bit of off-the-beaten-path fun, I strongly suggest you contact the organization for a chance to visit this fascinating and otherwise inaccessible local landmark. Who knows, you might even come out with a different idea of what a ”guided tour” can look like.

Fort de Caluire


Association OCRA-Lyon
Champignons de Paris: The famous mushroom and their city farmers, France Today (16 Mar 2015)
The Last Mushroom Farms of the Paris Catacombs, Messy Nessy Chic (25 Feb 2014)


  1. Héllo , je suis l’un des guides qui vous a permit de faire cette visite , jolies photos et merci pour la pub .

    Peut être a un des ces jours ici ou la .

    • Bonjour et merci pour votre commentaire. (Ici Paul qui traduit pour Noora, qui commence ses cours de francais demain!) Ce fut un plaisir de visiter la champignonnière. Nous revenons à Lyon pour les fêtes et sommes intéressés pour d’autres visites. Pouvons-nous vous contacter par e-mail ?

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