A mire may not be all it seems, particularly on Dartmoor. We tramped through the damp and drizzle, heading towards the blue spot - Leftlake Mire - that we'd identified on the map. Far from being an unpleasant sticky bog, it was beautiful. A vast pool, rather dark and desolate and cold. We swam across the great expanse, and looked back to see an arch silhouetted against the sky; quarrying used to go on here. We then attempted a bit of, er, synchronised swimming; an experience bizarrely enhanced by the appearance of our limbs in the water; it looked as though we'd all been a bit overenthusiastic with the fake tan.