Why did the ancient Bretons erect over 20,000 menhirs at Carnac? What was the purpose of the alignments, rectangles and dolmens? Was it all just for games? Can anyone make sense of the place? Carnac is the largest megalithic site in the world. Up until now it has kept its secrets. In this book, beautifully illustrated with rare prints and new diagrams, dedicated Carnac sleuth Howard Crowhurst reveals the sophisticated geometry at the heart of this ancient temple.