In the heart of Porto and a few minutes from downtown and the historical center.
The view over the Douro's river is fantastic.
You can come from airport to city by subway , bus or taxi
By subway is like 45min and 3€ per person more a less and then you need to walk to the apartment like 15 min
By bus is like 1 hour the price is the same of subway and you walk 5 min to the apartment
And by taxi it cost 30€ (maximum) and is like 20 min to the apartment.
If you come by car it is really easy too, and 20 min from the airport.