Strange weathered formations abound. The horizontally grooved pillar is particularly conspicuous. It's on the north edge, about 20m NW of the cairn.
It has possible cup marks at it's foot, a couple of which may be artificially pecked, or may only be solution holes. Better lighting, or a rubbing might make this clearer.
Beneath this are some of the many overhangs which could easily have been effective rock shelters before they silted up.
Another 10m or so along the path from the formation, is a boulder which appears to have definite pecked cups, less weathered, on a few of the side faces. I'm still not 100% sure though. Single cups being tricky to diagnose and all.