My teaching experiences have mostly required me to look for some kind of shelter, and in most cases, roofs and ceilings have been held up by walls. The pendulum for and against open-plan primary school settings in the UK swings constantly one way and another, and is, if anything a reflection on the fact that no one particular model is superior. It is, after all a question of teaching and learning styles and appropriacy. I should confess however, that I do like to keep out distractions so walls do serve a purpose beyond keeping schools standing upright.
Learning Without Walls?
But there are places in the world where learning occurs in the great outdoors - of course there's a whole area of non-traditional or specialist learning that happens outdoors, but then there are traditional classes that are delivered and studied in open ground, under the shade of trees and so on; but of course, much of this is because of lack of choice especially in parts of the developing world.
So why is there a great trend by educators in the industrialised world to rip down walls, where in other places, walls would be the START? Well, there-in, is the attempt to reach out; to empathise, share knowledge and ideas, to join-up learning experiences, to free minds and (for me, the moral obligation) to bridge the digital divide.
Are you listening Microsoft?
See http://educationaltechnology.ca/couros/ for more.