Julian Cope presents Head Heritage

Roy, not wishing to be an obstructionist, I do think Avebury's World Heritage status may have a bearing on any changes made to the site. I've tried to find what the restrictions are but haven't been able to come up with anything pertaining to this scenario.

You may be able to find the information or alternatively phone English Heritage and ask them.

http://whc.unesco.org/en/faq/