Nothing. Just one warning for driver with GPS: it turned out some GPS's, ours included, don't take you to the hotel based on the address published in Booking.com! If you see your GPS starts to take you out of town, simply head to the very center of historic Sintra.
Right at the center, modern and very comfortable room, helpful staff, excellent breakfast. We stayed 2 nights, parked the car in front of the hotel (limited space, but I understand the hotel has additional spaces by valet) and explored Sintra historic center and Sintra's main attractions by combination of foot and bus (note: you can easily walk, on a nice shaded steep downhill path, from the Moorish castle to the hotel).