BEWARE! Mrs RBD and myself lost our way and nerve on open moorland attempting to find this double stone row at the weekend. The path towards it from Langstone Moor is indsistinct and I think we cocked-up on Cocks Moor. When the weather changes - as it did both quickly and spectacularly for us you'll need a compass - we alas, didn't have one. At 1600 feet above sea level Burl and Petit report that this is the highest row on the moor.
In "From Carnac to Calanish" (1993) Burl rates this site as a "3" - runied but recognisable. This is the same grading as that given to nearby Langstone Stone Row which we had earlier walked through without recognising the ruin!
Park at Smeardon Down and take a compass. Good Luck.
Amongst Crossing's (1912) helpful advice on how to avoid getting lost on Dartmoor is a memorable line about turning your jacket inside out so that the pixies can't bewitch you!