>...it would need something to make it stand out from those lovely rolling Wiltshire hills; thus, the flatness of its constructed bonce leaves one in no doubt that it was designed rather than naturally occuring...<

Yes, that's an interesting idea Pilgrim (assuming that it wasn't white for very long). Peter's idea also that, "...that is what the flat bit on Silbury is - a platform for a nipple-like building!" is also interesting (given that there are a few other tit-like hills in the area :-) The 'nipple' may not have been a building but a more solid addition that's now long-since vanished.

It's fun and interesting to speculate - the seemingly intentional 'flatness' at the top of Silbury just screams out that there was either something there or that something once went on there, and the value of discussing that possibility might just lead us closer to understanding what that 'something' might have been.