Pressure point

I've blipped this fungal-looking cromlech more than once before. and the quip that there's not mush room inside has been done to death (if not by me.)

Today I was struck by the contrast between the licheny surface of the vertical supporting stone and the dimpled underside of the capstone.
 (I've boosted the contrast to accentuate this.)

Bearing the weight for a few thousand years.