The listing and other reviews describe it perfectly! It's in a great location in the historic center--a 12-minute walk to Quinta da Regaleria, a five-minute walk to the National Palace of Sintra, and just a few minutes to the shops and restaurants in the center. Be aware that there are some steep hills to get to/from the flat and that cars might not be able to take you there or pick you up from the door, so pack light and be prepared! Likewise, the nearest "big" grocery store that I found (a Minipreco) is in the more modern part of town by the train station, so if you plan to cook, you might want to get food before you arrive. If you decide to walk to/from the train station, I found the easiest route to be along the Volta do Duche (the "driving" route via my Apple Maps route), as the hill is fairly gentle there and there are nice wide sidewalks. Thanks, Ana!