The Murs à Pêche site, located in Montreuil, is the last witness to the fruit culture that made the city famous under the Old Regime and until the aftermath of the Second World War. The walls are a unique example of the use of local topographic and geological resources, drawing on their thermal qualities. Privatised and fragmented by urbanisation, long reduced to a wasteland, the gardens of the fishing walls are today a nature reserve that the City of Montreuil intends to preserve, and enhance by the development of the biodiversity trail project. The path of biodiversity is defined by all the paths and scents allowing you to travel through the heart of the Saint-Antoine district. It reactivates paths lost as the neighborhood deteriorates and gives access (physical or visual) to a rosary of spaces that are all different environments welcoming the flora and fauna of France. The course he defines will be the support of a didactic discovery of the biodiversity of the Paris Basin, in connection with the history of the site and thanks to adapted furniture and information materials. The objective of the project is to develop and preserve a unique natural space through actions to safeguard, restore and enhance biodiversity in urban areas.