Sesimbra is very quiet and only the sounds of the sea kept us awake. Fantastic location, nice, clean, modern hotel. Service a little mixed with some waiters less enthusiastic than others but that's a minor gripe. The beach is great, not too busy (in September). Loads of good restaurants as long as you like fish. Lisbon is an hour on the bus, less if you're driving yourself. Local buses were fine for us though.