I've been looking through some photos of Avebury I took in 2007 which got me thinking. I wonder if certain perimeter stones forming the actual Great Circle itself meant more than others? This is a photo of part of the North West Quadrant and whilst the majority seem to have been your 'bog standard' type of sarsen albeit of various sizes and shape, one does stand out amongst the section shown and I wondered if that was just by chance or a purposely chosen stone? I've called it the 'Bart Simpson' type as there are others within the site that do take on this somewhat angled flat-topped head 'look'. There must have been easier and lighter stones to use instead of the more bulkier ones so why use them?

https://picasaweb.google.com/100525707086862773355/NorthWestQuadrant?authkey=Gv1sRgCL7x6vuurYyNvgE#5734157955949986722