I stayed with a friend in Lisboa, and Rua da Rosa is at the center of everything, especially close to Principe Real with tons of restaurants and full of nightlife. Small cozy flat on 3rd floor without elevator but worth the climb up with the terrace on top. Key difficult to get used to, but will get used to it with some practice. Note that to turn on the lights in hallways, you have to press the buttons with little lights at the center. The plain white ones are for ringing doorbells. Just the heads up about the room structure: it is a flat with the restroom/shower right next to the bedroom without a door, so it might be a bit awkward. But hey, the chances are you're gonna stay with your family or a close friend, so no worries.