Brian Byng's book "Dartmoor's Mysterious Megaliths" mentions settlement remains to the north of the B3357. He also talks about a fallen menhir and the fact that it might have lined up with Pew Tor on the winter solstice.
The field, now open access, is full of stone and also full of bracken. Even with a sketch of what I am trying to find I fail miserably. Nevermind, I decide to explore the hut circles and enclosures, again hidden amongst the bracken.
I found four huts, I think!, none of them easy to photograph, then crossed the road to head back towards the stone rows.
Shortly after crossing the road I came across the biggest stones I have ever seen used to build a hut circle...if thats what it is. The hut itself was not large, perhaps 15ft across but the stones used in the construction are not your usual random moor stones.
The hillside is dotted in circles and enclosures, one even features an 18th century millstone, balanced on granite uprights, inside its perimeter.
Slightly to the north west of the western end of the northern stone row (are you following?) there is hidden amongst the grass what Byng calls a stone circle. The National Park booklet about Merrivale calls it a cairn. I thought it looked like a small circle, there are three or four stones in the circle plus one in the middle, not very cairn like.