Well, I’ll keep an open mind on whether it's stood in its present form for millennia but, based on Sanctuary’s observations there, I’m 95% sure that it hasn’t. In fact the more I look at it (and I confess I haven’t been there) the more it looks like a folly and something constructed by someone who didn’t know the faintest about dolmens – how they should look and how best to keep them standing.
The jury’s out but I really do recommend anyone who’s interested in Trethevy and its long-term prospects to look at Sanctuary's DVD (and book when it comes out).