As a reception function for the two museums of nature and archaeology, the museum pavilion must offer access to the ticket office, a modular space for groups and vernissages, and an exhibition space that marks the start of a visit to the two museumsLike a watchtower, the new reception pavilion is a quadrilateral nested in a corner of the surrounding wall. This position anchors it in the architectural ensemble and gives it prime visibility opposite the rue des Châteaux entrance. The pavilion becomes a new interlocutor, in dialogue with the Penitentiary and the Ancienne Chancellerie. The rectilinear driveway alongside the Ancienne Chancellerie leads unambiguously to the pavilion, a wooden sculpture into which we are invited to enter through the high pivot door, the only visible opening from the street. A simple element that positions itself neither as a replica nor as an adversary, but as a courteous and serene partner. The project is inspired by the medieval style, and its appearance evokes a timeless architectural language.

The wooden facade was chosen to differentiate it from the two mineral heritage buildings, signalling its function as an entrance. The compact layout leaves the circular walk around the Penitentiary free. From the reception area, the underground exhibition is organized in the shape of a cross, serving both the group area and the checkrooms. The exhibition room for the theme of anthropization is open-plan and forms the lower link with the exhibition in the Ancienne Chancellerie. The main exhibition room, on the other hand, is built under the volume of the Penitentiary. From the street, a large paving slab links the three volumes and leads naturally to the museum entrance. Around the Pénitencier, the open-ground design allows for the generous addition of vegetation, inspired by natural environments and requiring little maintenance.