I hope someone has information on this for Egbert.
In 2007 I took the bus from Santiago to Porto after my Camino to do a few days of sightseeing. I didn't have a guidebook with me but knew the old town was fairly small and planned to get a map when there. Unfortunately, the bus didn't go to the Porto bus station as I had assumed it would but dropped us all off on a street corner somewhere. It was Sunday, everything was closed, no one spoke english (and I knew NO portugese), all those who also got off the bus were busily being picked up by their organized rides - I spun around in circles and almost cried. Where was I? Luckily a taxi driver approached (at least I think he was a taxi tho nothing on his car nor in his car advertised such) and in pantomime promised to take me to a cheap hotel. Which he did, the hotel was fine and it all worked out.