I take your point that 'tidied up' sites often have the best access, precisely because they've been tidied up. But here the gravel around the stones doesn't bear any relation to the access - there doesn't seem to be a path to the circle?

Perhaps there was originally gravel (or stones) roudn the stones. Hmm. Perhaps someone can say.

Anyway I think you can have good access without over tidying. Depends on the site really, whether the soil is muddy or not! Lovely flat well-nibbled grassland makes an easy approach, assuming it's well-drained.