From THE HAUNTED COTSWOLDS by Bob Meredith:
“One warm summer afternoon a family from the Midlands, visiting the mound decided to picnic on top of it to enjoy the view. They laid a large table cloth on the mound and loaded it well with food and crockery.The day was still and warm without a breath of air about.During the course of the meal the table cloth suddenly leapt into the air, scattering food and the people.The family were so upset by the incident that they quickly packed everything away and hurriedly left.”
Townies eh? Who brings crockery and table cloths to a prehistoric site? Not surprising they got scared off :-)