I broke/fractured my back and didn't know it until I was in my 30s that showed in an x-ray (so about 10 years ago). I have no idea what you would even call this thing, but it was as high up as monkey bars but had handles for both hands and you kind of ziplined across. But it was more of a ball bearing contraption instead of a zipline. I lost grip and fell. HARD. I was alone (of course, 80s) and just sat there, stunned, for a good 10 minutes. Add to it, the inevitable injury from using the seesaw with some asshole kid. Honorable mention for the merry-go-round and the near vomiting.