The 'Labyrinths' (many of which are actually Spirals) in the Solovetsky Islands are interesting in this respect. That was a shamanic culture and the spiral is held to have been a metaphor for death / the unconcious

http://en.wikipedia.org/wiki/Stone_labyrinths_of_Bolshoi_Zayatsky_Island
http://geophoto.ru/?action=collection&id=917