Wasn't about to disprove it at all. I reckon it's certainly both the tallest and the greatest!

I asked because I was reading of a mound the other day and thought, "feck me that's big!" and would like to compare volumes etc. with Silbury.

One thing I would say is - is it a 'mound'? As it's made up of lumps of chalk (i.e. lumps of rock) it's a huge cairn in my book, but that's just being picky I s'pose.