Also featured is something called PlayPumps---I'm absolutely fascinated by the idea.
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It's also something I saw in the book Gaviotas.
See-saw pump“In the open-air Gaviotas preschool, the children’s see-saw is actually a pump in disguise. As they rise and descend, water gushes from a vertical pipe into an open cement tank. Over the years Gaviotas technicians have installed these in thousands of school yards, using kid power to provide villages with clean water. This simple, inexpensive pump has revolutionised rural life across Colombia for people who used to haul their water in buckets from muddy tropical rivers.”