The ridgeway reappears past it on the orange OS map, going about 100 metres east of the church.

Looking at <a href="http://www.themodernantiquarian.com/image.php?image_id=10848">this image</a>, there seems to be a barrow on the hillridge south of Alton Priors, with the village on a line from Adam's Grave to the possible barrow. Closer inspection of the photo reveals what I think is a clump of trees & streetmap has a barrow closeish. But then again that all sounds suspiciously like leylines :)

Anyone know whats to see at SU091582, its labelled Henge on streetmap?