Principles of megalithic architecture

Appeared 6000 years BC, megaliths continues to question searchers. How were the materials brought? What was the measurement used at the time? And above all, why were they built?
To Howard Crowhurst, who have studied them for many years, there is no doubt that every installation of the site of Carnac in Brittany is based on a sacred architecture. His works on sun rises and falls in equinoxes and solstices reveal the triangle structure 3-4-5.

"the most beautiful triangle" according to Plutarch, also present in Middle Ages Cathedral architectures, Egypt pyramids and the Temple of Salomon. So many examples of existence of an architecture inter-planetary and universal, based on primordial values present in nature.