Except that it hasn’t. Not exactly.

The Avebury that tourists see is in large part the creation of a wealthy amateur archaeologist who owned the monument in the 1920s and 30s and restored it as he saw fit. Not content with re-erecting the fallen stones, Alexander Keiller, the marmalade millionaire, shredded the village, creating a landscape that, while fascinating and mysterious, is largely an invention.

Old photographs have recently come to light that show Avebury to have been a thriving community before Keiller arrived. But shops, garages, chapels, guesthouses and pubs didn’t fit in with his idea of prehistoric scenery. So he saw to it that they disappeared.

Villagers were evicted and foundations grubbed up, and with them went all the layers of genuine history - the evidence of continuous human occupation - that had accreted here since neolithic times.

And not only was Avebury village reinvented by Keiller, but so too, it seems, were parts of his precious prehistoric monument.

In addition to re-erecting fallen stones, Keiller marked missing megaliths with concrete posts. Unfortunately, at least one of these is thought to mark a spot where no stone ever stood. And then there’s the case of the upside-down sarsen. This prominent eight-foot giant was re-erected in 1911 by Maud Cunnington, the grande dame of Wiltshire archaeology.

But Keiller couldn’t stand the woman, so in 1935, he had the stone uprooted and set in concrete six feet away on its head. According to archaeologist Mike Pitts, an adviser to English Heritage, Keiller was right to reposition it but wrong to upend it.

So how much of what we see at Avebury is down to the marmalade millionaire? That, it seems, is all part of the mystery of the place.