If you’re looking for a pristine playground to take your pristine children, one where they can go down primary-colored plastic slides and land onto a cushioned surface, this post may not be for you.

Flaming stone fire pits, wonky swings, lopsided wooden forts, stacks of hammers and saws, and even an abandoned automobile turned into a play den: Kolle 37 is not your usual kind of kids' recreation ...