During a wander round the wonderful Preseli area we came across several examples of stone wedges in clefts of rocks.
And even a wedge and apparent hammer stone just waiting to be posed in a convenient crack (no damage to any stone was done, and the tools returned to where they were found)
Mike Parker Pearson's latest book Stonehenge, a Brief History gives some details of the ones he has examined.
Click to embiggen
