scenic sand dunes covered in lush marram grass leading to an open coastal marshland in authie bay near berck, france, under a

sand dunes marram grass coastal authie bay berck france nature landscape tidal beach wetland overcast misty wilderness ecosystem environment flora biodiversity green brown peaceful tranquil fortmahon somme hautsdefrance marquenterre picardy northern europe sea mud slikke schorre salt marsh english channel horizon untouched estuary grassy meadow cloudy sky habitat ecology conservation serenity panoramic