Does anyone else recall how, in the Pandorica Opens, just before the Doctor gets put in the box, & Amy & Nestene Roman Rory are talking, you hear tribal music, with drums & what sounds like war-cries in the background. It sounds like the sort of thing you might have expected from a tribe of the ancient Britons of the time, if they were either just going to war or were celebrating a battle. Yet there is no suggestion of any such tribe being near the Roman camp or the formation of megaliths.