The town of Sanguinet is bordered by the Landes forest. It is on the edge of this natural area that the multi-sports complex is located. A network of concrete posts and perimeter walls supports a self-supporting roof slab. We chose concrete for the construction of these large-span beams. Its use is sometimes criticized from an ecological point of view, but in this particular case, it seems to offer the best performance compared to metal or wood structures. The factory where the panels are manufactured is located in the neighbouring commune, less than 15 km from the construction site. The agile, limestone and sand necessary for its manufacture are naturally present in the region. The thickness of the self-supporting slab and the intrinsic thermal inertia of the concrete notably limits the layers of insulation often derived from petrochemicals. The space freed up on the ground makes it possible to accommodate a hemicycle seating that focuses on the central sports field. The facade is completely glazed and gives a view of this green landscape. The objective is to show the sports performances but also to think of the place as a sanctuary, focused on nature facing it. The large glass panels can be opened and the sports field becomes semi-outdoors, interacting directly with the natural elements that surround it. In this way, the building becomes evolutionary and its vast open central space can accommodate theatrical and musical performances. The pure lines that compose it call for contemplation and serenity. The changing rooms and reception areas are contained in one wing of the building, while the other, overhanging on the natural terrain, has a self-supporting roof defining a semi-covered area, where only the hollow roof structure and the posts define a hybrid zone whose ground has remained natural. One can then imagine nature taking back its rights and creating a wild garden, with tall pine trees growing to cross the structural framework of the roof beams. The building is designed to encourage these exchanges, interpenetration, accidents and the poetry of a nature that always finds a way.