I'm extraordinarily proud of our ancient monuments - all of them! And I have no doubt our ancestors were far more technologically advanced than popular belief gives them credit. But I also believe the granary idea is far from feasible.
I'll happily eat my hat (the one made of cake, not the woolen one) if proved otherwise!
I'm biting my tongue here. I really don't want to be unkind. Good luck with proving it. I'm betting my hat is safe (even the cake one - until the time comes that I have no other cake and have to resort to eating it out of desperation)
G x