First time i went to Dyffryn Ardudwy about 15 years back, it was a bright sunny day and a little breezy, and the huge oaks at the site were blowing quietly in the wind. The place struck me as being immensely peaceful and i set to with camera, snapping away.
I had loaded up some high res film with the intention of taking some b/w photos see:
http://www.themodernantiquarian.com/image.php?image_id=3397
While i was busy checking out angles etc, the place was deserted, but everytime i took a picture i had the really unnerving feeling of being watched, and expected to hear the large cobbles crunch and slide beneath sandalled feet behind me.
I stayed in an old house made of stone at the tip of the LLeyn called Gelliwig and spent each morning walking the lanes, i found the whole area to be almst charged with a subtle 'presence' - perhaps it was Blodeuwedd waiting to bloom again...