My school had one of those. One day we got the idea to tie one of the kids to it around his waist and make him run around to spin it. I still remember our teacher asking "where's Willy?" once recess was over, then looking out the window to see him desperately trying to untie himself.
My school had one on dirt. The panels were wood and had a hole in it. Finally, one day, we were playing and a kid’s foot went down there and got fucked up. He was like a rockstar coming into school next day with stitches and crutches.