Casa Azul is one of my favourite hostels thus far - and I have been to quite a few. The hostel itself was absolutely lovely, both clean and functional with reasonable house rules. The location was perfect for all the sightseeing and food opportunities. The breakfast served in the morning was a huge spread with various tasty options. The hosts and guests were extremely easy to get along with, I particularly enjoyed how much interaction and local tips we managed to share. Everyone was respectful and it was truly cosy like a home. Unfortunately I only had one day to spend in sintra but I would definitely stay here again if I were to return. Highly recommended!