Archigram's massive archive just cracked open all over the Internet. While they're famous for their crazy concept studies and futuristic proposals, one of the architecture collective's realized projects--since demolished--was an adventure playground in Calverton, Milton Keynes, Buckhinghamshire. Which sounds like you should have heard of it, or know exactly where it is, but I haven't, and I have no idea. [Aha, a civil parish in a borough in a ceremonial county in the northernmost district of the south-east region. Very well, carry on, then.]
Anyway, 1972, an indoor play space with a shop and bathrooms, maybe a courtyard play area in back, all surrounded by giant berms, a retractable-looking sun shade there. Frankly, I'm not feeling it. Great picture, though.
Projects | Calverton End Adventure Playground, Milton Keynes [archigram.westminster.ac.uk]