Just a thought: interesting there's no mention in the report of the 'high-status burial chamber' (http://www.themodernantiquarian.com/post/57641/images/lismullin.html) that had been previously mentioned in the newspapers, just a short refererence under "Other Sites" to a medieval souterrain 'located approximately 50m from the enclosure'. I suppose the uncovered part of the mound could be soil covering the roof of a beehive souterrain and that the 'high-status burial chamber' was an error.