I've been searching the internet for years to find a reference to this cairn. My Grandfather was the Policeman on Benbecula during the 14-18 war and my father, Angus Campbell, claimed that he and his friend Roddy Campbell pushed over the central stone in the cairn sometime around 1918. He had a different version of the story of the witches which he was told by Roddy Campbell's Grandmother. BTW the boys were trying to catch two black rabbits that went into the cairn, they dug down in the stone pile to find the rabbits but realising they were near the base of the central monolith they decided to push it over instead. There's probably a lot of archaeological desecration to be laid at the feet of teenaged boys.