There is a small limestone outcrop amidst a wide expanse of open moorland with some good flat areas, although disappearing under the turf and often covered in moss and lichen. Being limestone, and so easily weathered by the rain - and it does rain occasionally here in Scotland! - there are many patterns and shapes in the rock that are tempting to see as art but which are just natural weathering. It was easy to find plenty of cup marks here, but I'm unconvinced that many of them are human-made. But there are certainly a few that are quite credible.
The day I was there it was dry and sunny, and had been dry for a good few days. I think it's worth a return visit in damper conditions when the surface of the rock will look quite different and see if there are any more convincing signs of prehistoric decoration.