Burl certainly does call this a 530m row but Jeremy Butler in his epic Dartmoor – Atlas of Antiquities claims it is only 369m long.
The difference, he claims, is due to the the restorer who “mistakenly added 180 yds to its length”. He puts the original ending at the 1.2m high stone in the row of stones N of the low bank some 300m from the cairn circle.
He also claims it was probably a single row originally as in the areas where there is a double alignment some of the stones are set across the row suggesting they were re-erected incorrectly.