>>I look at tiompan's photo at http://www.themodernantiquarian.com/img_fullsize/39584.jpg for example, and nickbrand's photo at http://www.themodernantiquarian.com/img_fullsize/13499.jpg, and I really don't see anything esoteric there; just stones that may have formed posts for pens.
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I dunno, Littlestone. I'm going to leap into the thread here so apologies if these points have already been raised. From a practical point of view...

Are we thinking here of corralling animals on say an overnight stop on a long drove road whilst en route to market?
Our ancestors weren't stupid, if they wanted animal pens and the available material was stone, why didn't they build solid walls with one gateway? Why do half a job? Why have gaps that needed constant reinforcement and vigilance against predators?

Also, on or near the top of a hill is the least sheltered spot, how would they get water to the stock kept there? Hard to tell with the scale of things, but animals can jump a fair way, goats, no chance of penning in either of those areas, sheep, maybe, cattle could just step over the stones, deer would bound out, 6 ft fences aren't any probs to a deer, pigs, were they ever 'herded'?

Or, are we thinking of say a lambing pen? For sheep not brought to the valleys for lambing? Somewhere on the high grazing ground that would provide shelter in winter for the ewes and their young, somewhere to keep the lambs safe from predators? Again, a solid stone wall is much more effective, think of wolves and foxes easily gaining access through those gaps and think of that concentration of sheep in that small area for a period of time, what would they eat and where would the water supply be?

They are only my thoughts, I'm not discounting the corral idea, we ought to look for other than ritual and esoteric use, I'm just wondering how it would work in practise.

Rune