karst spring fosse dionne in tonnerre, france

waterway canal river water town wall tourism reflection village bridge estate house castle building ruins fosse dionne tonnerre karst spring fed rainwater from surrounding hills its drainage channel armanç france center old construction buildings french city cityscape ancient architecture basin bourgogne bourgogne-franche-comté burgundy cascade circle collecting waters divine europe historic historical hydrogeological hydrogeology hydrology jurassic landmark limestone medieval monument morvan mysterious outdoor outflow pit rural source stone summer travel washhouse washing yonne