Stonehenge 181
Image by pce1975
Stonehenge

Stone shifting 5

Damn good point. In fact a strong pointer to the possibility of alien involvement!
In fact, EH don't seem to have considered this "logistical" stuff in their dating studies. If I had another lifetime I might be tempted to look at doing a paper suggesting they relocated the bluestone settings several times specifically because they were in the way of subsequent construction works.

But for our purposes, we'll keep clear of any new theories, for obvious reasons. One utterly audacious hypothesis is quite enough!

Talking of audacious hypotheses, I mentioned the project to one of the Neanderthals who said, between sips of beer
"they put it on a sledge, waited till Winter, built a ramp out of snow and pulled it up that"....

Steve, on the subject of your question, how did they get the trilithon stones through the sarsen circle, it seems that the sarsen circle did indeed pre-date the trilithons by a long time and with some degree of certainty.

However, I came across this statement:
"Of the 30 standing Sarsens, only one is of an uncertain date".

That'll be it then, I'd imagine.