algae blue coastline Lofoten Islands low mountains natural nature norway norwegian ocean plant pool rockpool rocks sand sea seaweed shore tide view water beach cloud coast England english Great Britain horizon shine shingle sky Sussex wave wet apartments buildings gravel home house houses seaside dark ebb landscape light river rural stream wild abstract background green rock rolling round rounded saavem stone stones texture cliff face sedimentary united kingdom wales welsh aerial aerial roots colors colours dunes glistening glossy greenery growing growth layers levels low tide mangrove growth mangroves ocean edge ocean waterline pebbles plants receded receding receding tide rocky root network Roots rough salt-resistant sand dunes scrub security strength strong support tidal tides waterline