 Cathedral, City Porto Oporto at Stock PhotoCathedral, City Porto Oporto at Rio Douro. The old town is listed as UNESCO world heritage. Portugal, EuropeImage id: 746-89060architecturebridgecatholicchurchcityscapedawndom luisdouroheritagehorizontalmuseumold townoportoportoportugalportuguesereligionreligiousreligiuosreliogiousscenescenicsitetypicalunescoworld heritage sitewrought iron 