what do we make of this?
As we leave Avebury village, and coast down-hill towards Beckhampton, an extraordinary feature appears on the left. A grassy hill, incongruously regular, sitting placidly on a low plain.
True, nature can throw up all sorts of odd, suggestive shapes - you might easily assume that this was one of those. But if you walk up to it, walk around it, see the flat top and the smooth curve of its base, you have to recognise that someone's been showing off again.
Local tradition had it that this was King Sel's (or Zel's) Hill, and the King was supposed to be buried at its heart, dressed in full, rich armour (maybe even gold).
The idea wasn't entirely fanciful. The locality is littered with round barrows, in which the locals had found the remains of ancient worthies who had decided to take their worldly goods with them. Silbury Hill must have looked like an extremely large round barrow. In theory, it should contain the possessions of an extremely powerful (and rich) personage.
Over the last few centuries, many official attempts (and god knows how many unofficial attempts) have been made to excavate the Hill and reveal its treasures - without any tangible result.
The most recent such attempt was by a team from Cardiff University - in 1968. This excavation was performed in association with the BBC, who broadcast live reports from the trenches. The Beeb had rather talked up the King Zel story, with alternative suggestions that Silbury could be a boat burial (just such a burial had recently been found in Eastern England).
So it was that, before a breathless nation, the cameras revealed - absolutely nothing. A Great Moment in Television. Oh, they did find a jar - containing mementoes left by a previous excavation.
However, once visions of gold and kings and boats had evaporated, the Cardiff excavation proved the most useful there had ever been. It established, once and for all, that there was nothing concealed within Silbury Hill. It also revealed that the Hill had been built in three stages (at that time, there were still those that insisted that Silbury was a natural phenomenon - perhaps with some human landscaping). It also revealed the age of the engineering - that it was probably begun before the Avebury rampart and ditch, and finished before the stones were raised - making Silbury Hill nearly 5000 years old.
At that time, Silbury may have been the highest man-made structure in the world (pre-dating the Great Pyramids of Egypt). Today, it is still the highest man-made mound in Europe.