We have a lot of stone circles in Scotland, and have had some experiences in a couple.
Here is Daviot -
Loanhead of Daviot Stone Circle Feature Page on Undiscovered Scotland
And Easter Aquhorthies -
East Aquhorthies Stone Circle Feature Page on Undiscovered Scotland
As you see Daviot has a second ring that turned out to be a crematorium site from the Bronze Age. I met the 50 or so spirits that are still there.
Easter Aquorthies is much lighter in feeling, and there is one male guardian there.
Both are still currently in use.
There are many more smaller circles all over the place. Some are on the official OS maps, but many more are hidden in long grass at the sides of farmers fields and not even recorded as such. You only see them at the end of winter when the grass is flattened. There are also the Harestanes and woofstanes - again few are recorded, and a lot of large standing stones that are disappearing as new roads or housing is being built. Many of those are still used as altars too.
I have visited a few at midnight on full moons or solstice and the places are ....magical.
As to what I think stonehenge is - or how they built it. I think it was a meeting place, and the stones have travelled from distant corners. Each would represent a clan or group, and the leader of that group would sit infront of that stone.
I believe the top stones were placed during winter - after the area was filled with packed snow. This way it would be easier to drag the top stones on the snow into position, then wait for the snow to melt. The whole thing could easily be an ice house built with a wooden roof. In the summer simple woven panel sides would suffice.
It may have had one opening that aligned with the spring low sun, but I don't think that was the only reason for it being built. More of an architectural bonus - like having your house facing south.
I believe it was a place of council. A meeting place of leaders, Possibly a trade hub as well or certainly a summer fair.
It is better to talk to your neighbours and trade with them than be at war with them, so I believe this was the main reason - a place to air grievances and work on solutions. This was all before the time of kings and the feudal system.
