serene coastal scene at authie bay with a group of horseback riders silhouetted against the vast shoreline and shimmering sea, sky

authie bay berck beach horseback riders horses equestrian shoreline coastal sea ocean sand tidal low tide wetland nature landscape adventure freedom exploration fortmahon somme hautsdefrance marquenterre picardy northern caacute te daopale france europe mud slikke schorre salt marsh tranquil peaceful vast horizon sky clouds blue panoramic seascape tourism travel outdoor recreation environment marine wilderness