In Fosses, in the Val-d'Oise (95), the Letourneur farm is currently undergoing a major renovation to welcome the Archéo-site of the potters of Lysieux, a new cultural venue dedicated to the history of ceramics. Led by the intercommunal body Roissy Pays de France, this project, which will become a new branch of the ARCHÉA Museum, envisions an archaeological trail, exhibitions and workshops open to the public. Construction, started in early 2025, is expected to allow a spring 2027 opening, according to the timetable currently in place.
The story of this site is particularly compelling. Since the first discoveries in 1990 by the Jeunesse préhistorique et géologique de France (JPGF), research has underscored the importance of the Ysieux Valley in medieval pottery production. Spanning between Fosses and Luzarches, archaeologists have uncovered traces of around a hundred workshops that operated over more than a thousand years. Thanks to rich clay deposits in the subsurface, the valley once served as a major ceramics hub. Pottery produced in the area has even been found during excavations in Paris, all the way to the royal Louvre palace site.
In the heart of Fosses' old village, close to the Saint-Étienne Church, this new heritage facility is taking shape. The project envisions a full restoration of the Letourneur farm, whose buildings will house a permanent exhibition devoted to manufacturing techniques, everyday objects, and the history of the valley's potters.
The future archaeological site will extend beyond the farm’s buildings. Visitors will also be able to follow an outdoor route laid out around the archaeological remains, including ancient potter’s kilns that will be protected and showcased. A wide roof will help preserve these remains while keeping them visible. The project will also include green spaces and a new reception building built in pisé, a rammed-earth technique echoing the materials once used by artisans.
Assigned to the architecture firm Frenak + Jullien, together with landscape architect Delphine Elie, this restoration project aims to preserve the rural charm of the site while making it more accessible to visitors. It enjoys particular backing from the Île-de-France Region, which awarded the site the Patrimoine d'intérêt régional label in July 2018.
Beyond uncovering the ruins, the future Archéo-site des potiers de l'Ysieux will also offer activities for the general public. Pedagogical workshops will help visitors better understand the artisans' craft, the firing techniques, and the different steps involved in ceramic production. The permanent display will also feature archaeological objects from the excavations carried out in the valley.
An artist-in-residence program for ceramicists is also planned to bridge traditional know-how with contemporary creation. The goal is to offer a lively venue where visitors can both discover the history of local craftsmanship and engage with the current practice of ceramics.
Following the preventive excavations conducted in 2024, the project moved into its first phase at the start of 2025. The initial work focused on restoring the façades, foundations, timber framing, and floors, laying the groundwork for the new reception building and the protective structure to safeguard the ruins.
The year 2026 is devoted to interior and exterior developments, to greening spaces, and to setting up the permanent exhibition. The public opening is planned for spring 2027, although at this stage no precise inauguration date has yet been announced.
In the meantime, curious visitors will have the chance to explore the construction site on an exceptional tour scheduled for Saturday, October 17, 2026, from 10:00 to 11:30 a.m., as part of the National Architecture Days. Led by the project’s architects and its landscape designer, the walk-through will help attendees understand the work underway and the anticipated future arrangements. The free tour is open to ages 12 and up, with registration encouraged at the ARCHÉA Museum.
With this new cultural venue, the Ysieux valley is poised to unveil a portion of its long-hidden history. Starting in 2027, visitors will have the chance to see how these northern lands of Val-d'Oise sustained the daily lives of people across the Paris region.
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Location
Ysieux Potters' Archaeological Site
2 Rue de la Mairie
95470 Fosses
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