blue box bridge calm city cityscape clear cross crossing curve dundee hill house houses locomotive over perspective rail river scotland sea shadow signal sky still Tay track tracks train water appearance clouds cloudy craters distance distant evening glowing half-moon heavenly hidden light moon moonscape orbit orbiting out-of-shape partial phases reflection shadows shape shapes southern sky sunlight daytime partial-visibility southern-sky visibility brick cantilever coast Edinburgh estuary famous Forth grey iron landmark metal paint painting Queensferry railway red rocks shore span stone tower gray night-light partial visibility road suspension cannon capital castle cliff cloud defence defences defense defenses flag flower flowers fort fortress garrison green precipice rampart rock soldier sun tree trees wall walls white