This box if a fire alarm. This looks like an old-school device and who knows if it's even still used today.
Like most parks there are a set of lights along the periphery or at least along the paths. I almost wonder why there was a need to set up parks at public schools around the city. The only other one I'm aware of is at McDade although in that case it's in the back of the school off of it's south Indiana Avenue location.
There will be more pictures later! It's about more desecration, but not necessarily the same as what I found over at Shedd in the summer of 2008.