If nobody has ever seen this before, it's a catalog of map symbols in .pdf format
from a Francophone website. I haven't messed around with any of these yet but the range of application should be obvious.

http://www.paris-pc-gis.com/MI_Envir...mapping_fr.htm

There are lots of good symbols to use, though it's more geared towards the actual and utilitarian. After looking through the list I was unable to find any standing stone symbols, the purpose of my search. So once again I am forced to ask the world that great question that has troubled men since times immemorial: "Where's my Cromlech?"