I don't know if Craigh na Dun really exists. I think the writer changed the name of the henge she used in her books. I think she might have had the hence "Clava Cairns" in her mind. In that henge there are also two stones together, and it looks as though they were split. Through such a stone Claire would have travelled back in time. Check out the next side to see pictures of the stones and see if I'm right. http://www.undiscoveredscotland.co.uk/inverness/clavacairns/
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