Dartmoor looms as a dark and cloudy presence on the horizon of the lush green cream-giving meadows and endearing thatched villages of Devon. It is an open, bare landscape of grass and heather, boulders and sheep, studded with granite tors. But the apparent uninviting emptiness belies a rich history. There are many ancient Bronze Age tumuli, hut circles and stone rows hidden deeply in the grass; more obvious are mediaeval crosses and boundary marker stones, and there are industrial-era mines, quarries and tramways, the dark grey stone making them seem older than the century or so of actual age.