I stopped and asked a farmer at Penfras-uchaf farm he pointed me back down the lane and said I could park in front of the gate that leads to the path that leads to the stone....Ideal.
down the tree lined path turn left into a field then right into another field and there it is in the corner. About 7ft tall and taking Mynydd Carngwch as it's inspiration possibly dating to the same time as the giant hilltop cairn.