The apartment is very conveniently located: at walking distance from both Sintra and Portela train stations, as well as a good supermarket (Pingo doce) and of course the old Sintra: just a beautiful walk along the boulevard to the Sintra National Palace and a very pleasant one hour uphill hike (good exercise) to the Castelo dos Mouros and the Palacio da Pena.
It is really close to the ‘electrico’ that takes you to the nice Praia das Maças (but also a fast busconnection by Scotturb and the beautiful views of the Cabo da Roca.
The trains will take you to Lisbon frequently and quickly (with a lot of stops on the way that will take you wherever you want to go in 30-45 minutes all day and evening: download the trainapp CP and bus/tram Carris).
If you come by car: there is a large parking place just a flight of stairs away.
You can cook your own meals (kitchen is well equipped) or go out for lunch and or dinner (recommended: Bosque, next to the Cultural Centre Olga Cadaval: great vegan place, also great for meat eaters. You won’t miss the meat).
The beds are great, the bathroom is fine. Cable television in the living/dining room (and the movies on the Hollywood channel are subtitled, not dubbed).
The host Pedro is very friendly indeed: he came immediately when I had locked myself out, even though he was surfing in Cascais.
I can recommend this location as a place to spend several days and check out Lisbon, Sintra and the oceanside. You will have a good time.