I spent a pleasant afternoon surveying cairns, stone rows and standing stones on Greenbarrow & Trehudreth Downs. I found Trehudreth Downs W Cairn, a round grassy mound with an irregular surface measuring c. 20 yards in diameter and 3 feet high. There is the footprint of a stone structure measuring c. 5x4 yards in the E Arc of the cairn. It is located at SX 12475 72749.
Marked on the OS map. I can't say for certain that I found this unless it is the small mound aligned just to the west of Trehundreth Downs Stone Setting / Row.