I received this card in the UNESCO tag and it's already my 2nd card from Porto :) It's even a bit similar to the previous one, because I can recognize some buildings, but still this one is different (because it shows a wider view) and I like it very much. I learned that this postcard shows the Ribeira district of Porto located on the bank of Douro river. I've never been to Porto (actually, I haven't been to Portugal at all), but it seems to me that this place has the special "medieval" atmosphere, which I really love :)
The alluring district of Ribeira is made up of medieval streets and seedy alleyways. It is a crumbling but fascinating place, ending at a riverfront square ("Praça da Ribeira").
With photogenic traditional boats floating at the quayside overlooked by colorful ancient houses, this is the most picturesque spot in the city and the place everyone loves -- UNESCO did too, and declared it a World Heritage Site.
If you leave the city without visiting Ribeira, you have not experienced Oporto.