There's a children's book called, "Not A Box" by Antoinette Portis. It is one of the cutest ones I seen lately. It describes my childhood. I could spend hours playing with an empty box. My dad worked at a grocery store, so our supply was ENDLESS!!! Now a days, it's a little harder to find boxes. When we moved to Boston, I actually went to a storage place and bought them.
I know how much fun a kid can have using their imagination and creativity with this recyclable toy, so I did the next best thing. I bought a cardboard playhouse. The beauty was it took my less than 10 minutes to assemble and the kids have already been playing with it. It's not as great as what I had, but on some level it's almost better.