The town of Rosny-sous-Bois organizes a specialized dawn walk to identify the rare migratory birds nesting in the Coteaux d’Avron park. Tracing its origins to these hills have been a significant regional landmark and a sanctuary for biodiversity within the densely urban metropolitan area. The event reinforcement the regional identity of Seine-Saint-Denis as a territory that values and protects its unique natural slopes and wildlife. Visitors can experience a peaceful and educational morning using professional equipment to discover the secret life of the city’s feathered residents. This initiative has a strong social impact by promoting quiet culture and environmental stewardship among local families and urban explorers. For ornithologists it affords a vital dataset on the nesting patterns of urban bird populations in the Paris outskirts and suburbs. The walk ensures the legacy of the hills as a protected green sanctuary is recognized and preserved by the regional community.