>>If all four stones are joined up they make a lovely rectangle, something impossible from lattitudes further to the north and south. (which would give you a wonky rectangle instead).

I've heard this point before but not been entirely convinced by it. It's one of those things where I suppose it's difficult to argue that an approximation would be good enough because accuracy is central to the proposal.

However, the rectangle is not an accurate one. The dimensions are (quoting Aubrey Burl): long sides 79.9m and 80.3m (0.5% difference); short sides 32.7m and 34.2m (4.6% difference). Consequently, the angles are not right angles (89d 25m, 89d 33m, 91d 2m and 90d 1m).

I vaguely remember him saying somewhere else (but cannot now find the reference) that for the true rectangle to exist Stonehenge would have to have been built in the Irish Sea!

That is not to say that astromonical alignments do not exist at the Station Stones. They do but not in a way that forms a rectangle.

There is, I think, another view on the Station Stones - that they were used to determine the centre of the stone circles (which are not concentric with the henge). Not sure I understand this point but, if it's true, it could imply that the Station Stones were not part of the original Stonehenge.