Odd playground equipment,...

...which looks like dysfunctional bicycle rack. I recalled I have somewhere seen similar odd playground equipment as in Stefan's shot. Inspired by Stefan, I decided to go and find it. So, I chose a little different route for my morning walk as usual, and found it in one schoolyard. This strange object made me remember also an old book 'Catalogue d'objets introuvables' by Jacques Carelman.

So, do you know any other odd objects like these? Or do you know how this playground equipment is supposed to be used? Maybe I should go lurking around that schoolyard to find out how kids use it, and probably get arrested in doing so =D