I doubt it, at least I hope so!! It's not visible from the road, at least not anywhere in a 500m radius as it's on a sort of plateau.

Did you turn right just at a little bridge before the long bend through a valley? If so you won't have a hope of finding it unless you've got a map and compass or a gps. The best way is along the main road, the last lane before the bridge heading west branches off and uphill to a farm yard, you pass through the yard and follow the track past the gate. Once through the gate head north west through the field and the circle should be almost immediately visible about 100m away or less.