Ponte Dom Luis I bridge over the Douro river and the old town of Porto at dusk, Portugal, Europe

arch bridges arch bridge arched bridge atmosphere atmospheric light atmospheric attractions attraction bridges bridge cities city center city centre city constructions construction cultural monuments cultural monument cultural sites cultural site dawn deserted dim douro river douro downtown duero dusky dusk empty europe's europe evening atmospheres evening atmosphere evening hour evening mood evening scene evening shot evening skies evening sky evenings evening famous place gustave eiffel heritages heritage historical old town historical historic center historic centre historic city center historic city centre historic old town historic inner city inner town landmark light atmosphere light mood light scene midtown mood municipal nobody no one no people northern portugal old city old district old town area old towns old town place of interest ponte dom luis i bridge ponte dom luis i porto portugal portuguese rio douro river rio douro rivers river sight southern europe south europe steel buildings steel building steel constructions steel construction steel structure tourist attractions tourist attraction tourist landmark town center town centre town travel photography twilight unesco site unesco world heritage sites unesco world heritage site unesco world heritage unesco world hertiage site unesco world site unesco uninhabited urban environment urban world heritage site world heritage