After two ladies took pity on us and drove us to where we were supposed to be, we still were far from making the GPS work. Luckily, we asked a person in the street who pointed to us that instead of Porto, we put Vila Nova de Gaia as the city and it worked perfectly. We certainly learned how helpful Portugese people are in showing their historic mastery of navigation.
It is on the other side of the Duoro from Porto and here's the fantastic view we have from our 3rd floor apartment. All worth the climb. The Port factories claimed by Porto are all here too...so write the name down now.