An earlier contributor mentioned Pilgrimage.
This is such a common feature in so many ancient societies and several
modern ones, that it would be surprising if it was not relevant to
high-status sites like Stonehenge. In some societies, pilgrims were allowed
to cross hostile borders, and wars were suspended for major pilgrim
festivals. Joint custody of pilgrim shrines was a major way of of
organising society above the single-settlement level (think 'amphictiony' in
classical Greece), and disputes about pilgrimage could have interesting
results (eg the Crusades).
The difficulty of the journey is part of the point of a pilgrimage, and you
might do it only once in your lifetime, like the Haj today.
If there was some way of investigating this, we might learn all sorts of
interesting things about Neolithic society in Britain. I suppose the
isotope analysis of skeletons already mentioned is an obvious starting
If long distance travel becomes difficult and expensive again, perhaps
heritage tourism will become more like pilgrimage. I have only once been
inside the Dome of the Rock (as a little boy), and I don't suppose I shall
ever go there again; it's getting a bit too exciting there right now, and in
any case, I'm not sure if non-muslims are allowed in any more; but I'm glad
I had the chance to do it once.