Mike Pitts on his blog asks; What’s that hole in Soane’s model?
The centrepiece in Stonehenge: Monumental Journey is a cork model from the Soane Museum, brought out of store. ...What’s interesting, and I hadn’t expected, is to see that the ground has been modelled as well as the stones. It’s not just a flat board, but a gently rolling, crumpled surface. And what jumps out is what can only be the hollow left by an excavation, apparently by someone in search of buried stones, near the feet of the leaning trilithon stone 56. Did anyone know about that before? And if we didn’t, how many other furtive old hollows might have disturbed what we think of as ancient, pristine ground?
I think it might just be the hollow formed as the stone moved - Gowland's careful cross section of the rear of the stone before he straightened it shows there was a hollow that had filled with turf and mold. Or had someone dug down into this softer soil?