This turned out to be interesting, not only were there public bathrooms that have windows that overlook the CP.pt rail at the train station, but the fact that it is at the train station and is for all practical purposes the primary shopping mall in the area. Dozens of stores, and a large fast food restaurant area on the second floor. There are escalators. If you are going to the hillside tram or the top of the mountain, then cut through the mall to the far side street and then it is a short distance to the tram. PS. Google Maps will tell you that you have to walk nearly a mile, as it displays the one-way car traffic as the walking traffic. Don't believe it, you can walk from the circle down the hill to the tram.

I went to the Station (Estação) Shopping Centre in Viana do Castelo. I see they different retails shop.