The hill is actually a truncated grass covered pyramid about 120ft high and more than 600ft across, weighing an estimated half a million tonnes. Silbury, just south of Avebury, took more than 100 years to build and work began, according to the radiometric dating that has been carried out on bits of vegetation and other material recovered from its innards, about 4,400 years ago.
Over the centuries, various lunatics have riddled the ancient chalk construction with tunnels, mostly in an attempt to find treasure.
The latest was in 1968 and was at, quite extraordinarily, the behest of the BBC. They hacked into this unique national treasure with impunity to make a series of gimmicky history programmes. They even built a recording studio in there.
When Silbury started caving in on itself a few years ago, a plan was hatched to repair the damage by pouring in hundreds of tons of chalk paste to fill the voids. By the start of next year Silbury should be safe, its voids filled, making now about the last time anyone will be able to venture down the tunnels.
Modern genetic analysis reveals that after the ice-age glaciers receded from Britain about 8-10,000 years ago, these islands were repopulated by probably two waves of peoples - one from what is now Spain and Portugal, the other from the north and east, from what is now Denmark and Norway.
And it is from these peoples, who built Silbury and Stonehenge, that most British people today are descended.
But as to why our ancestors built these huge monuments, we can only guess. Stonehenge was certainly some sort of astronomical instrument - and the various standing stones not only of Wiltshire but further west in Cornwall and to the far south in Brittany, France, may similarly have served some sort of astronomical purpose.
But Silbury? The official line from Jim Leary and his colleagues is that it must have been inspired by "ritual". The trouble is, this is pretty much what archaeologists always say when faced with an object they don't understand: it must have something to do with religion.
"This is a big ceremonial mound," Leary insists. "It's not a big clock, it wasn't built for a bit of a laugh, or to give people something to do."
He points to the fact that there is none of the usual random detritus and debris associated with ancient secular building projects - no discarded meat bones, no ash from fires, bits of pottery and so on. "This suggests that the site was always treated with some reverence."
In addition, large, solid "sarsen" stones (boulders similar to those at Stonehenge) have been found embedded in the chalk; one theory is that these represent the souls of the dead.
Maybe the whole thing is a sort of "virtual mausoleum". That's the current theory. But there have been a whole host of rather more outlandish ideas concerning Silbury over the years.
A long-standing legend holds that the hill is the tomb of King Sil, a statue of whom (in gold) supposedly lurks in a secret chamber to this day. This mistaken belief that, like the Pyramids, Silbury Hill is full of treasure led to a series of attempts to dig into the mound, beginning when a team of Cornish miners were recruited by the Duke of Northumberland in 1776 to dig vertically into the hill from its summit.
In the 19th century, more tunnels were dug in the quest to find a hidden chamber. Then in 1968 a huge series of corridors and chambers were excavated as part of that BBC project, in what can only be described as an act of archaeological vandalism. No treasure was ever found, but that did not stop the speculation. In fact, a delightfully bonkers belief system has arisen in recent decades which attempts to link ancient sites like Silbury and the Pyramids in Egypt with alien visitations, and even structures on the surface of Mars. More UFOs are "seen" round here than anywhere else in Europe.
Barring a massive earthquake or a meteor strike, Silbury will probably be here for another 4,000 years and who knows what archaeologists then will make of the strange tunnels that were dug and then, only a few decades later, filled in. No doubt they will come up with as many theories to explain our actions as we do to explain what went on more than four millennia ago. And no doubt they will bear just as little relation to the truth. (Daily Mail)
