Set slightly higher up the hill from the stone rows, this is the biggest upright on the downs. The higher upright (of the group of three) can be seen on the ridge to the SE.
The reason why it is hard to find the settings on the downs is partly because of the gorse bushes. Although they do not cover the area they do have a habit of hiding things when looking from one point to another.
I found this from the Trehundreth Downs Stone Row. There is a good picture of this in Peter Herring and Peter Rose's 'Bodmin Moor's Archaeological Heritage' (Cornwall County Council - 2001). This excellent book writes "next to a cairn on Trehundreth Downs is a setting of three uprights in an arc, as if to define a forecourt-like area where rites could be performed against hills under the great expanse of the upland sky". Although their description is a bit strange to what is on the ground and their interpretation surprisingly flowery compared to the rest of the book, it proved very useful to help me find this.