For my money the easiest approach is from the point where Sir William Hill Road coming out of Grindleford meets two footpaths and turns into a track at SK2245 7742. Easy parking on the lane. Between the two footpaths is a third track visible on Google Earth though not shown on the OS map. It heads towards the circle and forks – take L fork and then you can pick up track(s)on R to the circle. However, the ease is relative, and I would recommend using GPS.
My interpretation of the site would be that it feels as if its designed for an ‘audience’ to the S observing activity with the dramatic skyline as a backdrop.