Solstices have always held a peculiar fascination for me: the turning point of the year, the hinge on which the seasons change. So when I walked across England from Dorset to Norfolk – some 400 miles along the Icknield Way – for my most recent book, The Green Road into the Trees, I timed it so that I would be in Avebury for dawn on the summer solstice.
Friends asked why I didn't choose Stonehenge instead, along with 20,000 other people. But that felt wrong. Archaeologists think the famous ring of stones on Salisbury Plain was built to celebrate not sunrise but sunset, and for the winter solstice, the turning point of the year on 20 December, when the long nights start to shorten. Moreover, recent excavations suggest it was one of the largest Neolithic burial grounds in Britain. So the New Age ravers who flock to Stonehenge each summer have not only come at the wrong time of year, they're also dancing on a graveyard. As it's also the only time when visitors are allowed inside the circle, it's more like a rugby scrum than my idea of fun.
Far better to walk 25 miles further north to the equally atmospheric ruins at Avebury, where they also know how to party and, as the largest stone circle in England, there's plenty of room; the village of Avebury has sprawled around the prehistoric site, so there's even a convenient pub at its centre.
When I arrived late the night before the solstice, crowds had already started to gather. A police sign by the pub declared that dogs would be used to search suspects. And there were plenty of likely suspects sprawled around the stones, many of whom had settled in for hours. A samba band had started up and the accompanying dancers twirled blazing flame-throwers around their heads. "Now that's some tricky stuff," said a teenage girl next to me in a strong Wiltshire accent.
The atmosphere was like a raucous bonfire night, with added druids. A man with a bearskin mask passed among the crowds. The accessory of choice was a tall wooden staff on which to lean while watching samba dancers or patrolling police – also useful for warding off any travellers' dogs, eyeing up all the exposed human flesh which, after a day's sunning, looked as tempting as a barbecued sausage.
The advantage of having walked all day to get there was that I was tired enough to fall asleep against a stone. First light was at 4am and there was a while before sunrise. Rather than join those who had been partying all night around the southern end of the circle, I wandered to a quieter area in the north-east. A few people had gathered by the big stones that were once, when upright, set as a triptych and orientated towards the rising sun. Loud snores were coming from a sleeping-bagged bundle at the bottom of the largest stone, where someone was going to sleep through this year's dawn.
A tall man in a grey cloak with a staff approached me. He had the languid, tired manners of an Anglican vicar and lived in Malmesbury. "Are you a Pagan?" he asked, as if it were the most natural question in the world. I mumbled the sort of non-committal generalities I usually do when someone asks if I'm a Christian. My hesitancy was reinforced when he then asked if I was a Christian and I had to give a similar response.
"Paganism," he explained patiently, "is being tied to a sense of place, of being rooted in a landscape. If you're drawn to Avebury, then you're probably a Pagan." I nodded politely.
"Not that it's easy being a Pagan," he sighed, and leant on his staff to peer moodily at the ground. "The problem about Paganism is that because it's all local, and about local places, we don't organise ourselves on a national basis very well." For a moment he sounded like a Liberal Democrat.
"What matters to a Pagan in Malmesbury is completely different to what matters to a Pagan in" – and he cast around for an exotic example – "say, Devizes."
"But trying to organise Pagans is like trying to herd cats," he added, with bitterness. "It's solstice day, the most sacred day of the year, and most of them have gone to the wrong part of the circle to celebrate!"
I wasn't complaining; it felt like I had the solstice to myself. Leaning against the most comfortable stone in the triptych, I ate the fruit I had in my pack, some strawberries and blueberries that had chilled during the night and tasted delicious.
The sun came up, hard and fast. From my vantage point, the clear, early dawn light picked out the stones with a far greater clarity than they normally had for me, mixed as they were with bits of the village. I asked myself a basic question: why is Avebury in a circle (or for that matter, why are most prehistoric monuments in Britain)? A circle is more difficult to construct than a square.
But a circle is what children form when they hold hands. It is what adults would like to do and like to have – a community of equals: a round table. But it rarely happens. It is aspirational. It is making yourself whole with others. It is the shape of the sun.
I leant back against the rock of the megalith and closed my eyes. Far off I could hear the sound of the samba players in the other meadow, beating up a storm.
'The Green Road into the Trees: An Exploration of England' by Hugh Thomson is published by Preface (£9.99). He is speaking at the Kings Place travel festival on Sunday