but there's a strict rule that posters shouldn't promote their own gigs. Just to demonstrate how tightly it is enforced here is an image of something I did make - http://www.themodernantiquarian.com/post/40717 - just watch, it'll be dileted by the morning. Just see ...

That shape - of those cairns - is actually quite difficult to build nowadays. It left the oral repertoire centuries ago, I would guess. I relearnt going round corners with circular sheepfolds. The cairns are very similar in profile to a late-Viking shield boss and they were active here and skilled builders in stone - but they had no use for horizon markers ...