Hi Jim
The stone in the Keiller pic looks handcarved, to me, but I'm no rockart expert.

This is the sort of beauty that may be best revealed in late winter after all the vegetation has died and rotted. As it was already down all that time ago, one wonders if the turf may have reclaimed it and that it's still there just under the surface...?

I'm intrigued by the name, too. 'Kenward' isn't a million miles away from 'Kennett' is it?
J
x

At first I thought 'well maybe it's to do with the way the rock was created in layers' but if that's the case, surely every rock in the locality must look like that - so why should this one get singled out for an explanation? Which points toward the man=made idea.
I wonder what sort of rock it is.

"opinion on this?"

Tantalisingly greyscale? ;)

It would be a heck of a thing if they were man made, especially on sarsen.