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Former World Cup Climbers Open Bouldering Gym South of Paris

The two bouldering walls at Boulder Factory
Former French National Team members Mélanie Sandoz and Guillaume Glairon Mondet recently opened a bouldering facility in a town south of Paris, with the wall design and hold selection for the gym influenced by their time on the World Cup circuit. (All photos are courtesy of Boulder Factory)

Boulder Factory
Le Plessis-Pâté, France

Specs: Boulder Factory, a bouldering gym founded and owned by former World Cup climbers Mélanie Sandoz and Guillaume Glairon Mondet, opened on May 20th in Le Plessis-Pâté, a commune south of Paris. According to Mondet, when he and Sandoz met nearly 15 years ago, they wanted to open a climbing gym, but due to their busy World Cup circuit training and travel schedules, it was not the right time. In the meantime, they were working for Block’Out, a French gym chain, and explored a franchise gym project with the company, but they decided to continue waiting for a more suitable moment before opening a gym. At the end of 2022, they were ready to start planning and found a location for their facility in “a pretty nice building, close to our home, in a new commercial center,” Mondet said. They signed a commercial contract in 2023 before beginning construction in January 2026 and installing the walls that March.

Elevate Climbing Walls

Boulder Factory is housed in a new mall, which spans an estimated 60,000 square meters (645,835 square feet), Mondet said, with approximately 65 new stores and businesses, including retail shops, restaurants and recreation outlets. The development is designed around pedestrian access, so passersby can stop and check out the gym. Mondet said the team was fortunate to find this location because “looking for an existing building was not easy,” and finding one in line with their vision “was not possible,” so they opted to construct the gym in a new building.

The bouldering wall on the new gym's ground floor
“I think we had a little bit of luck to find this one,” said Mondet about Boulder Factory’s location. The facility’s main climbing area is positioned in front of the seating and bar area, where there’s a large window allowing people outside to see into the gym.

The gym features 415 square meters (4,467 square feet) of bouldering surface on two main walls, both of which are about 30 meters (98.4 feet) long and reach 4.5 meters (14.8 feet) in height. Because Mondet said “it’s a really small gym,” with about 700 square meters (7,535 square feet) of floor space, the area was split into two levels to maximize the climbing terrain. The building itself is about 8.5 meters (27.9 feet) tall, which allows the second wall to sit above and behind the first, so the gym “still has a lot of boulders,” Mondet said. He explained the gym’s goal is to provide a highly climbing-focused experience and dedicate space specifically to climbing, rather than include additional amenities. “No training, no warm-up, no sauna, nothing. Only bouldering and a bar, of course,” he said. “It’s only bouldering. That’s what we want to share.”

Another look inside Boulder Factory
“We were routesetters after our comp climbing careers,” Mondet said of himself and Sandoz. “Now, I’m still routesetting in the gym.” The setting team also includes Alistair Duval, who has competed in several World Climbing events.

Sandoz and Mondet used their unique backgrounds in professional climbing to inform the gym’s wall design, hold selection and routesetting, Mondet explained, noting that the two “want to share our passion for climbing” with all climbers. “I would say I try to have everything in the gym, all the styles,” he said. “There are slabs, there are some big overhangs, and we try to have everything at all levels.” The gym uses “only World Cup Holds,” with a lot of macros, Mondet said, and although the ownership team comes from a competition climbing background, they do try to incorporate outdoor-inspired climbing in their sets.

Walls: Usteto
Flooring: Tyyny
CRM Software: GestiXi
Website: boulderfactory.fr
Instagram: @Boulder_Factory

In Their Words: “I would say it’s a long way. It’s a long way to open [a new climbing gym], maybe especially in France; I don’t know in other countries. But for us, for example, to build just the walls and the bar, it was a little bit more complicated than we were planning. But I think it’s the same for everyone.” – Guillaume Glairon Mondet, Co-Founder and Co-Owner of Boulder Factory

Naomi Stevens

Naomi is a competitive youth team coach who has also worked at climbing gyms as a routesetter and personal trainer. After starting college at Colorado State University in 2017, she wanted to make new friends and found climbing, fell in love, and now climbing dictates most of what she does. Naomi earned a bachelor’s degree in Ecosystem Science & Sustainability, and when not climbing she enjoys baking, gardening and crafting.