The apartment in Aruda is beautiful and very comfortable. It is in a very quiet residential area and is easy to get around and visit by foot, uber or bus. There is free street parking all around the neighbourhood. At night, we slept with the front and back windows open along with the fan in the room, the temperature was great and we slept very well.
It is about a 15-minute walk to Belem where you have many sights to see, you also have 2 beautiful botanical gardens situated within a 5-minute walk.
We highly recommend a Tuk-Tuk tour of Lisbon if you are not here for long, it is an hourly rate and you can choose the areas you wish to visit; it gives you a great overview to determine areas you want to go back to walk around and explore. To get to Lisbon from the apartment, we took a bus, 1.80 euro per person and a 20-minute ride. If you are planning to visit the Castelo San Jorge, go early in the morning to avoid the crowds and long line ups.