Bumping this up, as it is on tonight between 9 and 10

"Orkney - seven miles off the coast of Scotland and cut off by the tumultuous Pentland Firth, the fastest flowing tidal race in Europe - is often viewed as being remote. Yet it is one of the treasure troves of archaeology in Britain.
Recent discoveries there are turning the stone age map of Britain upside down.

Rather than an outpost at the edge of the world, recent finds suggest an extraordinary theory… that Orkney was the cultural capital of our ancient world and the origin of the stone circle cult which culminated in Stonehenge."