The apartment and the location is fantastic! It’s the very center of the city, close to absolutely everything. The only downside of it - it’s a little noisy outside, which can bother you, especially at night. Windows don’t provide much protection of noise, so you can often hear people talking or singing.
Carlos is an excellent host - he was kind enough to pick us up at the station and drive us to the apartment, where we left our luggage even though it was before the check-in time.
We enjoyed staying at Sintra and will recommend Carlos’s place for everyone who are not too much of a light-sleepers.