The building is opposite to the famous "Pastéis de Belém" pastry shop in the neighbourhood of Belem. It can be easily reached by tram from the centre of Lisbon, the tram stop is almost outside the building.
The flat and room were very clean and cozy, with towel and kitchen appliances (and hairdryer!) The room does not have a window, but it does not really matter if you are planning to spend your time exploring Lisbon or attending a conference at the Congress Centre, which is a 20-minute walk from the flat.
WiFi worked perfectly.
Ana (the host) was very friendly and helpful. She replied to all my questions immediately before my arrival, thus making my first airbnb reservation a wonderful and stress-free experience.