It's a freshwater loch where the people of Skara Brae could have caught trout and eels. Most Neolithic people built houses with wooden frames. But on the Orkney Islands, there aren't many trees.

This rich past came alive in the Smithsonian Channel's documentary Aerial Britain: Scotland, which highlighted Orkney's ancient marvels. Among them is Skara Brae ... housed as many as 40 families.