Lovely stay at Márcia's place... I guess that the whole building was recently renovated because in the hall and the apartment was everything brand new. Full equiped new kitchen, she even has a Nespresso machine, so don't forget your capps ;) The apartment is situated at the back of the building where it is super quite! We slept every night with the windows open.
It is 5 min walk to the top of the Ponte Luis 1 bridge (no hills). From there you can take an elevator to get down to the river. We took always the stairs (don't recommend this route for older people) 3min walking from the apartment to get to the bottom (this route takes maybe 10min) Includes some nice views of Ponte Luiz.
At arrival Marcia gave us some nice addresses​ in Porto, which were very good.
Would really recommend this ;)