All over Central Europe lie numerous huge circles of giant stones, some predating Stonehenge and the pyramids. Modern archeology researchers like Mainz (Mayence) university's Joachim Bürger call it the first monuments of the Neolithic revolution and ascribe the first to people who weren't our direct ancestors. Implantation along rivers and elaborate astronomical orientation support a link with standardization as agriculture succeeded hunting-gathering. Near Vienna a circular settlement is reconstructed, with tombs and a palisade. Their precise uses as refuge, kraal and notably ritual site, remain speculative. The same goes for their total abandonment over a few centuries, possibly due to warfare, invasion, epidemics and/or a genetic mutation allowing milk consumption by adults.