In Burls ‘Prehistoric Avebury’ and various other books is the story which was told to journalist Paul Screeton.
About ’ a very sincere man ’ who fell asleep at Arbor Low and was visited in his dream by the ghosts of Atlanteans who instructed him in the henge’s ‘Purposes and dimensions’.
I’ve never come across the rest of the story, so can’t really shed any light as to what those purposes were......