if so the similarity with Silbury (and perhaps Waden Mound as well) is striking, and the fact that Marlborough Mound is now thought to date from around the same time as Silbury (2400bce) suggests a much wider, perhaps culturally related, backdrop.[/quote]

That's fascinating. I'd love to find out how widespread this possible cultural phenomenon is. I remember reading something about the possible prehistoric origins of Norman mottes on here before. Would love further investigation but not likely with the current cash flow situation.

Along the same lines, near where I grew up is Eddleborough Church built on a potential neolithic mound. It's huge, I've been to it an is definitely not natural. Some refernces online refer to it as definietly prehistoric and others say only possibly. This one refers to it as a barrow but it's much bigger than that and is comparable in size to Marlborough Mount.

http://en.wikipedia.org/wiki/Edlesborough#St_Mary_the_Virgin

Also it's within sight of Ivinghoe Beacon hill fort which is the start of the Ridgeway which leads you know where! If it is prehistoric the 2 must be linked. Could this have been connected as the start and finish of the journey from one end of the ridgeway to another?