The builders of the ancient stone circles in Britain and Europe were not primitive savages; they understood the cycles of the seasons and the movement of the celestial spheres and had a deep understanding of geometry which they encoded into the many hundreds of stone circles in this country and further afield using a standardised measure called the Megalithic Yard. They were utilising "Pythagorean" triangles two millennia before Pythagoras was born and could predict eclipses! So thought Professor Thom who accurately surveyed hundreds of stone circles using a theodolite, drew up their ground-plans and discovered their geometrical and astronomical secrets, many of which you will find in this book.
When it was first published, Megalithic Sites In Britain was the source of much controversy in the academic world, which has now pushed it all aside, but in its day Thom's work gained support from some notable academics such as R J C Atkinson and Sir Fred Hoyle.
Before reading this work you should probably read Alexander Thom: Cracking the Stone Age Code
by Robin Heath. There is also a BBC Chronicle documentary on the web called "Cracking the Stone Age Code" which you should definitely watch.
This is a very dry academic text which requires a good knowledge of mathematics, particularly statistics, geometry, trigonometry and astronomy. Because of this it can be tough going but well worth it.
Sadly the academic world will never do justice to Thom, at least not while the status quo prevails.
A classic work.