If you travel to Porto, please make a point to book with Maria and Manuel. Their place is centrally located, and very clean. There is a bakery, small supermarket, gift shops, and a restaurant literally steps away. 20 minutes walk will give you everything you need. The area is safe and interesting. They will help you navigate anything. I would suggest a walking tour as soon as you can. It really helped us get our bearings. They offer free ones every day, less than a 10 minute walk from the apartment. It is expected that you give them a tip after. Well worth it! This is a wonderful city.