The project is part of the water purification plan of Brussels North, treating the surrounding park which must be natural in order to prevent possible risks related to flooding. It is graftí onto the existing in order to create new relationships and different uses: a new public space for the people of Brussels, including a water recreation area immersed in an artificial marshy landscape. Recovering in an artificial way the essence of the lost place, will allow to welcome a variation of species, formerly present in the valley of Brussels. The sewage treatment plant, the recreation area and the wetland landscape are connected by a rhyzomatic infrastructure system transporting water to transform the linear flows into a loop. The wetland landscape is reactivated by the displacement of soil material, available in situ. By extraction, the hollowed out negative space hosts the marshes, and the full creates a new artificial topography that sometimes hosts human ponds or a biotope adapted to the marshy environment. The marsh water is fed by the clean water that exits the treatment plant, then reaches the recreation area and returns to the treatment plant. A sequence of constructed wetlands is therefore proposed, in which the filtering capabilities of the marshes and aquatic vegetation are studied. They are connected to a water flow system, by feeding and suction. The Senne is entirely uncovered on the site in order to regulate the risk of flooding, but also to accommodate the biotope living on the running water. The reliefs and basins formed by the extraction around the Senne allow to regulate the water movement. The recreational area is conceived as a place of experience and immersion. The visitor is an observer of the cycle, part of a whole where he discovers the pleasures of swimming and the different states of water. Natural pools, sauna, hamam, solarium, slides, fountains, waterfalls, walks, observatory... It is bathed in the visible process of a system where the different bodies interact with each other and the being becomes. A playful way to re-engage people, to the often invisible or neglected relationship of the water cycle.