We had a fabulous stay in Lisbon. The Barrio Alto district is in an incredible neighborhood where cafes, restaurants, bars, and small stores are ubiquitous. You are in the middle of party central.
The Momento restaurant is below the apartment and has a great menu. Order the Black Pig - can foot stomp that enough!
We were there in December with temps in the 50s. The cooler temps required closed windows and also limited the number of tourists in the streets at night. I could see where this neighborhood in summer could be jumpin' and noisy at night. So going to sleep before 2am, might be an issue.
If you are fit, you can walk down to the central city and waterfront. Going down is no problem. The hill back up will be a better test of your fitness.
Cristina (owner) met us at the apartment and greeted us with a bottle of wine, fruit, snacks, etc. I can't say enough about her hospitality. The most attentive that I have experienced in my many AirBnB stays around the world.
All in all, I give this property two thumbs up.