Pi in the Sky: A Revelation of the Ancient Celtic Wisdom Tradition by Michael Poynder
This book looks at the solar system and planetary geometry; crystal structures - stone age symbols and engravings, Ogham; Stone Age sites of Newgrange, Tara, Carrokweel, Knocknarea; alignments between energy lines and water course, cornicles to reveal the foundations of geometry and its application for healing in the wisdom traditions.