adlershof architecture berlin construction fire exit flight of winding stairs germany grate grated helical metal reflection reflections security shape shapes spiral stair staircase wentletrap bank barge boat calm canal channel concrete England english entrance exit footpath Great Britain light narrowboat path peaceful river Sussex towpath tranquil tunnel water access airport airport-terminal blue communicating communication directional-signs doors informative informing inside interior open open-doors passengers pedestrians signs travel travellers travelling way-out communicate curbside direction drop-off inform information message mobile mobility school shadow shadows sign student students sunlight sunshine transport words yellow abstract angles appearance background drain draining embedded feature flowing fountain fountain feature hole pebbles running water saucer-shaped shells texture textures water feature wet aged ancient antique decor dirty door doorway entering gate grunge handle historical iron key lock middle obsolete old ornament rusty vintage wood wooden caution close escape fire fire-door keep-clear keep-closed no-obstruction red risk risks risky safety warning wording announcement aware awareness depart directions leave leaving observant observe regulations rules rust visitors way out white barrier boundary cloud drystone farm field green hill landscape meadow natural nature sedge sheep sky slope spring stone wall conveniences glass lift over-pass windows advice black lettering notice notification out outlet welcome word