I went to Lisboa with 3 friends for a 4 days trip discovering the city and we had such a great experience, it's a wonderful city.
Taynara's flat is pretty well situated, not that far away from the metro and close to the nightlife district Bairro Alto. There is a small square in front of the door and a bigger one down the street which is really relaxing. Several lovely cafes and restaurants take place around and a supermarket as well.
The flat is not very big but suitable for 4. You have to live with the front door open otherwise there is no light inside, there is just one window so that can be really dark.