The wooden construction extended nearly two miles across Salisbury Plain more than 5,000 years ago, and would have served to shield the sacred site from the prying eyes of ordinary lower-class locals.
Trenches have been dug around the monument, tracing the course of the fence which meanders around the stone circle.
The dig's co-director Dr Josh Pollard, of Bristol University, said: "The construction must have taken a lot of manpower.
Monday, September 01, 2008
More Stonehenge Stonehenge 'was hidden from lower classes'