I've had one of those days....spent this morning down the road looking at a group of supposedly standing stones, (see Essa Stones, East Cornwall). OK so there are two upright stone in a field and nearby there are several other stones either laying in fields or built into walls.
The evidence that makes these standing stones and not just scratching posts seams to be that there was a barrow marked on the OS map of 1813 in a nearby field.
As I travel around Cornwall I often come across stones, especially on the moors, that could be menhirs, part of circles...or scratching posts! I am no expert on the matter but would like to know how those that are tell one from the other.