The site of the former Saint-Thomas leprosarium offers an opportunity to revitalize its heritage through the renovation of its old chapel and the creation of an introductory and discovery path.
Designed as a thematic walk, the trail invites visitors to reflect on the disease and the place of the sick in the Middle Ages. It is organized around the notion of the ostracism of lepers, revealing the mechanisms of exclusion that shaped medieval society. The path is punctuated by interpretive elements designed by the agency. Totems mark the route, engraved with eleven symbols known as “defenses” representing lepers and their relationship to the world of the healthy. The starting point, named “Le Grand Départ,” marks the convergence of the various access points (hikers and people with reduced mobility).
A careful signage strategy, combined with subtle tree markings, connects the various sequences of the site. This marking draws on a local tradition, whose preservation and integration into the project ensures its transmission. The route culminates in a belvedere overlooking the meanders of the Seine. This high point invites contemplation and extends the site’s symbolic dimension by evoking a spiritual elevation.
Special attention was paid to accessibility. Extensive topographical work enabled the creation of a parking area on a former road, ensuring accessible entry for all visitors. The project, carried out in partnership with the Regional Archaeology Service, also incorporated site preservation considerations. This approach was recognized with the award of the “Heritage and Accessibility” label.
The Saint-Thomas d’Aizier Chapel, listed in the Supplementary Inventory of Historic Monuments and dating from the 12th century, is the last remaining vestige of the former leprosarium, which operated for nearly three centuries. This former place of worship was in a state of ruin. Archaeological excavations, conducted over more than twelve years, revealed the site’s significance, notably through the discovery of 232 graves, while also highlighting the structural fragility of the remains. Abandoned in the 17th century and later used as a stone quarry, the chapel lost all of its buttresses. Despite several restoration campaigns undertaken at the end of the last century, the building remains extremely fragile today, particularly at the level of its heavily deteriorated walls.
The restoration project is based on a strategy of consolidation and enhancement of the existing structure, fully embracing its ruined state. The observed pathologies, mainly caused by water infiltration in the truncated walls, guided the restoration work. Some of the previous restoration work was removed in order to restore architectural coherence and redefine the appearance of the walls in keeping with the spirit of the site. A lead coping was installed to ensure the masonry is watertight and to guarantee its long-term durability. The facings were fully restored, and the corners of the base were reinforced with metal staples to compensate for the loss of the original structural elements.
The project’s approach is to reveal the missing elements without reconstructing them. The former buttresses are thus evoked through a “hollow” restitution, making their imprint on the structure visible. Certain stone blocks were replaced, particularly around the twin bays while the base of the foundation was reinforced. The facades were restored, deliberately preserving the crumbling sections in their deteriorated state, protected by a film and covered with a mound of earth.
