If you want to visit Lisbon, that is simply the best place to rent in the city. Why?
Firstly because it is very well located as you have eveything close to you, you don't even have to take the subway, and if you want to take it anyway, you can reach the "Matim Moniz" station in less than 5minutes by foot. Secondly, because it is located in the "old" part of the city, which means that the district is absolutly lovely and calm, you don't have to worry about the noise, and there are so many cool things to do as the flea market of "Campo de Santa Clara", the national history museum and the botanic garden near it. Thirdly, because the appartment is perfect; it is really cosy, well decorated, you have space, everything is new and fonctionnal, as you can see on the pictures. There is a sunny balconny with a stunning view of the st George castel and a really beautiful chuch, and you can reach both by foot in 15minutes, which is really great since those places offered a wonderful view of the city. Fourthly and last, the owners are simply the best, they are very welcoming and warm, and you can contact them anytime if you need advices or if you have a problem; for exemple, for the last day of our trip, they let us let our luggages in the flat as it was not booked that same day, because our flight was at 19:00, so we could enjoy the city whitout carrying it all day! :)
Well, I don't know what more have I to say to convince you; but do not hesitate more. This is the place you want to stay during your trip to Lisbon.