Until last winter, the 1st through 3rd graders at my school had no playground. A recess of unmitigated blacktop play is not such a good thing: it's hot, balls get lost over fences, thirty minutes of tag tends to lead to roughhousing, etc.
Moreover, playgrounds don't only build social and cooperative skills. Nor do they simply build imagination. They provide the kind of challenges - balancing, motor-planning, spatial awareness, etc. - that all learners need.
No matter how much SIG money the government is willing to hand John Muir, apparently they don't want to spend it on a playground. I have issues with privately-funded education, but when no one else is willing to take it on teachers and children are out of options.
Go get Muir a playground.