"It's not unreasonable [...] to suppose that some kind of cosmic "sky-ground" religion lay behind the alignments to the solstices and the equinoxes at Watson Brake and at the other early sites--a religion sufficiently robust to ensure the continuous successful transmission of a system of geometry, astronomy, and architecture over thousands of years. John Clark is in no doubt. 'The evidence,' he says, 'suggests very old and widely disseminated knowledge about how to build large sites. The building lore persisted remarkably intact for so long that I think we can, and must, assume that it was part of special knowledge tied to ritual practice.' Where did this special knowledge come from before it appeared at Watson Brake?"