Cannot recommend staying at Carla's flat enough.

As for the flat itself, it was very clean and in a convenient location - very close to Bairro Alto, and within walking distance of the city centre. We did not take public transit once during our stay in Lisbon (except to travel to Caiscais and Belem), but rather walked everywhere and this was very doable.

Carla herself as a host was wonderful - possibly one of the nicest people I've ever met! She gave us very clear and helpful instructions on how to get to the flat from the airport. She greeted us with traditional Portuguese cakes and spent a good half hour with us giving us recommendations for things to do and see, eat and drink!

Staying at this flat and having Carla as our host made our Lisbon trip far better than it would have otherwise been - as I've said above, cannot recommend enough.