A couple of sources quote two rings on orthostat walling on Warren Moor.
I parked up by the entrance to Park Farm and walked up the side of the park to the crag that overlooks Kildale, I then followed the path onto Warren Moor and walked down the eastern side of the dry stone wall for about a kilometre, never taking my eyes off the wall. I then retraced my steps along the western side, again studying every inch of the wall. I did come across some vague markings on the eastern side but nothing that I could hand on heart describe as a pair of rings.
This NYM rock art is bloody elusive stuff.