Robert Louis Stevenson was aware of the imaginary potential of the fragmented region of Thiérache. Sailing the deep waters from the Sambre to the Oise, on board of his boat, the author of Treasure Island, filled his notebooks with inspirations of this thousand-secret-landscape and its preserved wildlife. The leaves of willows, alders, and hawthorns, shivering under the flight of kingfishers and sand martins.