View over Douro River at sunset to Ribeira District, UNESCO World Heritage Site, Porto (Oporto), Portugal, Europe

travel destination photography horizontal colour image europe portugal portuguese culture outdoors sunset city building exterior no people porto oporto unesco world heritage site unesco ribeira district douro river river water cityscape elevated view sunlight incidental people colour color image color outside tourist destination travel nobody no one no one background people people in the background unesco world heritage sites world heritage site world heritage sites cities typically portuguese traditional culture tradition traditional traditionally portuguese european sundown dusk twilight x 2018m2 x printready