Yep, there I was growing up just two miles short of Chicago proper. We would pitch a tent in the back yard, which may have measured 30 X 40 ft on a block with fenced off lots side by side that went on for miles. It wasn't camping in the woods, but it was fun sleeping out there.
I never built a tree house. There was only one tree on our lot, but as I got older a friend and I would ride our bikes 8 miles to a forest preserve, and sneak off into the brush on our bellies through almost impenetrable hawthorn bushes and build a lean-too out of a few branches and a sheet of plastic. We would visit it from time to time finding it by following blaze marks we had left. We never stayed overnight. My parents were worried about "perverts" hanging out in the woods. I thought it would be safe, because it seemed like we were so far off the trail that no one could ever find us, but it was a no go for my parents.
When I was much much younger, my mother would let me take cushions off the sofa and chairs and move furniture around so with blankets I could make tunnels to crawl around under in the living room. Even then I appreciated how my mother allowed this. The only rule was that we had to make the living room usable again before my father came home.
