It's Neolithic, it's aligned with the Summer and Winter Solstices, and it's part of a much bigger complex of avenues and ancient sites - beyond that, nobody really has a clue. There was no TV or decent food, golf hadn't been invented yet - maybe it was just something to do. The latest theory is that it was built by Kodak as a long-term investment.
Making a henge
First, find some large pieces of stone, ideally about 4 tons each.You'll need about eighty of these. Drag them on wooden rollers all the way from the Prescelly Mountains in Wales (about 240 miles) and place them upright in a field. Job done!
If this is too much hassle, just use wood instead, as the builders of Woodhenge did.
Obviously, mud is not the ideal material for henge-building. but you have to start somewhere, and before Stonehenge, before even Woodhenge, came Mudhenge. Archaeologists are still searching for the exact location.
Great video of henges
The henge today
The henge is still with us today. Spinal Tap used its archetypal power to bring a sense of mystery and channel the ancient forces of neolithic times into their stage show. When the scale drawings were misinterpreted - Nigel Tufnel was always a misunderstood genius - the results were less than epic. A mighty construction was lowered onto the stage amidst the swirling dry ice - but it wasn't very big after all.
Not too far from Stonehenge is Avebury stone circle, which goes through and around the village of Avebury. It's a National Trust site with free access and in some ways is as impressive as Stonehenge - a stone circle on a massive scale. If you're visiting the UK, it's a great place to see, and it's very close to Silbury Hill and West Kennet Long Barrow, all neolithic era monuments.
This area is just off the A4 from Bath to London, so might be convenient for visitors as a stop on the way.
Also in the village is an ancient manor house and a good cafe/restaurant called The Stones. A great (free) place for children to have a run around while you listen to your Spinal Tap albums and channel the mystic energies said to possess the site.
As it's much less famous than it's brother henge, there will be less people in the way.
The Ring of Brodgar in Orkney might be the prototype for all henges: definitely no crowds there. And no buses.
How to spot a henge
The Comedy henge
Is there any other sort? Tony Iommi, guitar player with Black Sabbath, was interviewed tonight on the BBC - and let slip that the full-size replica of Stonehenge that Black Sabbath had commissioned for their US tour (in the 70s?) is still languishing somewhere in the US, because they literally could not give it away!!!
Where is it now? As the connections with Spinal Tap are so strong, it must be a historical icon in its own right now. And it's not very small.