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Can't blame the desire...
(sh.itjust.works)
Desire paths Desire paths can be paths created as a consequence of erosion caused by human or animal foot-fall or traffic. The paths usually represent the shortest or most easily navigated routes between origins and destinations. https://en.wikipedia.org/wiki/Desire_path
I really like this one, because something fun could be done to 'graduate' if to a full path. My first thought would be flat top stones as a sort of gentle staircase leading over the entire circle.