Cover story on Stonehenge in the new Smithsonian Magazine
Also online here:
http://www.smithsonianmag.com/history-archaeology/light-on-stonehenge.html
It may have been an ancient version of Lourdes, but the stones do
align with various celestial phenomenon, probably all interrelated as
the ancients did not divide up things like we do. To them the one
was related to the other.