We are traveling to Italy in early November, and on the way back we have a 12 hour overnight layover at Heathrow Airport. Since we've never been to London, we'd like to know if there is any sightseeing we could do over night. I know things will be closed, but are the major attractions still lit up so we take pics? We are three adults - so pubs are always good! Also, what about transporation? Any help will be greatly appreciated.