I can't put it better than this....
Gordon Barclay... Historic Scotland
I would argue that there really isn't such a thing as a 'henge' as a single class of monument. New dates for and recent re-analysis of the Scottish material suggests that this sort of enclosure, with the ditch inside the circuit of the bank, were built for over 1000 years, range in size from less than 15m across (Wormy Hillock) to over 100m across (Brodgar) and surround a considerable range of pre-existing structures (timber circles (Balfarg, North Mains, Cairnpapple), timber mortuary structures (Balfarg Riding School), stone circles (Stenness), cist burials (the North Mains site again - the ditch and bank are contemporary with the cists inside)). A better explanation than the 'national' class serving a single function might be that they represent the closing off of pre-existing sites that are problematic or dangerous. From analogies with later Irish sites it has been suggested that the internal ditch and bank do represent a defensive rampart, but facing inwards against what is enclosed.
Gordon Barclay
point is... that one mans Henge is another womans sacred area...
we will never really know what each place as used for.. they deal with concepts that are within the mind. - Spiritual etc etc... you can't excavate a feeling.. you can only guess at what happened within them...
WE process to them... do we really know that is what happened? nope.. we hugs stones... did they? Did the builders of one monument actual feel teh same when they saw another?
They have another purpose for understanding prehistory... but knowing the mind of the individuals is a bit far off jsut now.
Another day another WSI?