Photograph of Silbury Hill, Wiltshire, UK, by Greg O’Beirne. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. Courtesy of Wikimedia Commons: http://en.wikipedia.org/wiki/File:SilburyHill_gobeirne.jpg
