abstract appearance backdrop background cascade cascading color colored colors colour coloured colours drops patterned patterns rocks solid spray stone stone wall stones stonework surface surfaces textures varied water water-feature water-spray waterfall wet down germany gill Harz mountains moss river speed splash torrent gray grey water spray beach coast coastline pebble pebbles polished rock rocky round sand stony sundrocks Ceredigion chasm cliff deep Devil's Bridge gorge high narrow natural nature plants wales welsh Bode Bodetal Harz mountains Bodekessel bridge architecture building center culture design famous floor fountain France indoors interior old Paris square symmetry trade