Location, location, location! The apartment is a one-minute walk from the Ponte Luís I bridge on the south side of the river. It's an easy walk to the riverfront, across the bridge, or to the Mosteiro da Serra do Pilar across the park. And, Maria and Paulo are excellent hosts. Paulo met us at the apartment to show us around and give us info. The apartment is very well-furnished and comfortable. Truly, one of our favorite Airbnb's while in Portugal. The only thing to note is that it can be noisy at night (it is right across from the Jardim do Morro). If you are a light sleeper, bring ear plugs to block out some of the noise (and don't let that be a reason you don't stay there--it is well worth a minor inconvenience!).
This is a great place to stay, and I highly recommend it.