Astronomy
     Precession
             ANCIENT SKIES
     AXIAL PRECESSION
I did this research while serving at Taranhai in Anieth. I was there as an astronomy student for many years. I was also an astronomer on Earth, so I was able to better understand ancient ideas. See the book, Thorn  for my story.
Pole
         THE SERPENT
       & THE TREE
    Skies
                 ANCIENT
     EUROPEAN SKIES
    Girdle
        THE GIRDLE OF
             ARIANRHOD
         Numbers
                   NUMBERS &
         ANCIENT ASTRONOMY
Calendars
            STELLAR
         CALENDARS
    Observatories
              STELLAR
      OBSERVATORIES
    Constellations

     CONSTELLATIONS
Stonework
   Thorn
    Writing