Something to be said for the boxes. They can manipulate it themselves, enhancing creativity, which is where the real fun is.
When I was a kid I wanted a treehouse. My dad built me something shaped like our real house up on 10' legs. Basically a shed on stilts. He was pissed when I just wanted to go play with the redneck kids down the road, where we built a dangerous as hell ewok village WAY the hell up in an actual tree out of old pallets and stuff.