Stonehenge Begins to Yield Its Secrets
nytimes.com
nytimes.com
A more informative view, I think, is to assume it's practical. When I look at pictures of Stonehenge, it looks to me like motte and bailey. A literal motte and bailey, the military fortification, not the logical fallacy by the same name. A motte and bailey is a military structure that was extremely common in the middle ages.
There's a ditch around the outside, which is for defense against small groups of invaders. There's a big stone structure in the middle, which you can climb up on if attackers get past the ditch, using a structure that was removed some time later. The graves, cooking pits, and other things at the site are just signs of habitation.
But I also think calling Stonehenge a motte and bailey fortification is missing the mark. That's an easy enough interpretation that, if the archaeology supported it, everyone would accept it and move on. There's something more to it, and maybe we just don't yet have enough data to say what it is.
It would also be an extremely small fortification that would be exceptionally hard to build. So while that explanation might be worth examining, I think logistically you would need to explain why they wouldn't have just used wooden bound structures instead (which you could source more locally). It isn't like four stones make something fire proof.
Plus it entirely ignores other linked religious ruins in the area like the town of Amesbury four miles away (and their stones). And those clearly have no military purpose, and were also moved and resurrected.
I'm all for buying into a theory that Stonehenge had a purpose. But militarily? Meh. It is just not consistent with anything and doesn't make a whole lot of sense. It looks nothing like other military structures from the time.