Silbaby 17
Image by Dunstan

"Incidentally I don't see how "being at the bottom of a hill next to marshy and presumably boggy ground" but clearly built straight off the solid chalk spur of Waden makes it significantly different from Silbury."

Thats if Silbaby WAS on a chalk spur, we don't know that unless its excavated.. If it is ever excavated bet you £10 that there is'nt a barrow ;)

Thats if Silbaby WAS on a chalk spur
Well I just assumed Waden's slope continued underground and they built off it. It has to be something pretty solid else it would have fallen down.

"If it is ever excavated bet you £10 that there is'nt a barrow ;)"

OK. But to give it a bit of edge and concentrate your mind, if I win I want you to send the tenner to Tarmac.