It is 1.51pm. The tourist coaches arrive at regular intervals, bringing visitors from America, Norfolk and Japan to this pocket of Wiltshire. They spill down the coach steps and into the sunshine, stream through the turnstile, buy rockcakes, listen to audio-guides, pose for photographs. "Is it time," they ask, weary, heat-worn, "for an ice cream?"
They have come to see Stonehenge, the prehistoric monument a couple of miles west of Amesbury. Used as a burial site for centuries, its stones are believed to have been brought here at some point after 2150 BC, carried 240 miles by water, by brute strength, from the Preseli mountain in Wales. Later came sarsen stones from Marlborough Downs, and then, in 1500 BC, the Preseli bluestones were re-arranged into the horseshoe and circle that still stand today, though many of the original stones no longer remain, some just stumps below the soil.
Its construction is still a subject of much debate. Some suggest that the bluestones came not from Preseli but from nearer to the site, glacial erratics from the Irish Sea Glacier. Others speculate how 30 sarsen stones, weighing as much as 50 tonnes, could have been transported any distance at all. Just who built it and why remains the subject of much debate and the stuff of legend. Now a World Heritage Site, in 2002, it was voted by the British public as one of the Seven Wonders of Britain.
This weekend thousands of people are expected to head to this patch of grass between the A344 and the A303 to celebrate the Summer Solstice, the point in the year when the earth's axis tilts most towards the sun. Last year, despite heavy rain, more than 30,000 people arrived at the stones in time for the sunrise. Many of those attending are druids, who regard Stonehenge as "a temple to the alignment of the sun and the relationship between the sun and the earth and the moon". At a little before 5am they will herald the arrival of the morning sun with horns and drums.
It is a glorious place to celebrate the British summer. Around here the land is rich and green and fertile, its fields rolling and tumbling, and this afternoon birdsong comes, chucking and bobbing and buffeting the breeze.
The Simons are here from west Yorkshire, retired now, and motoring down to the south coast. Yesterday they visited the white horse at Avebury, another of Britain's prehistoric sites. "It makes you feel funny, knowing how old these things are," says Mrs Simon, as her husband removes his shoes and socks and wriggles his toes in the grass. "I suppose I find it reassuring. We like old things," she adds. "Castles. Stately homes. Stones."
By nine o'clock the light is fading, the sun going down over the wheatfields. Up on the hill, cars, camper vans, Land Rovers stop and pause, windows down, music playing. With the tourist crowds long gone, these are private moments, a lovers' lane of sorts. There are no audio guides, no brochures, the gift shop is now closed, and everyone turns to the sunset.
The stones look small from up here, standing like distant strangers at a party. Across the smooth, warm expanse of wheatfields, the sky has turned from steady blue to pink and golden and magical. The sun is a bloody yolk; it is hot wax melting; it is sinking and dipping into nothingness. We sit in our cars and watch, listen to the wind through the wheat, to the distant car radios, to the birds that make a bubbling sound - two-whit two-whit wheee! The sky is ablaze now, aflame with red and orange, and far below the stones seem like ash, like the day's cooling embers.
They stay until the very last, until the grass looks cooler, poorer now the gold is gone. The car radios jabber, and the lights of articulated lorries come blazing up the hill. A man climbs back into his car, rolls up the window, fires the ignition and drives off down the gravel road. Above him the sky holds a crescent moon, pale as a nail bed.
