Well, we're going off at a bit of a tangent there FW, and I actually I don't agree with you that etymology isn't a good source of info (especially when it's the etymology of place-names). One thing's for sure, the local Wiltshire dialect would have rendered the 'a' in Waden as an open vowel - ie Waaden, not the closed vowel suggested by Weedon. I suspect you would, regardless of the idiosyncrasies of early 18th century spellings, still have ended up with two very discrete renderings of those two names.

I tend to agree with moss when she says that the, "...Wansdyke is the boundary of the last British/Welsh land, not the modern Bristol Channel..." It's hard not to believe that the Avebury area, at the time of the early Anglo-Saxon occupations, did not still respect and represent aspects of pre-Roman culture, and the idea of a hill with a 'Welsh' Temple, as suggested by Weedon Hill, fits comfortably into that landscape.

But who knows, we're all still tossing ideas around here - unlike the 'academic' community who seem to be doing sweet F all.