them stay open. the largest box will be the main room of the playhouse castle. repeat with at least two more large cardboard boxes.
tape the three large cardboard boxes together in a cluster. if you have more large boxes, complete the square or rectangle with a box on the other side. use extra cardboard to close off the ends of the cardboard boxes that are not connected to one another. if you want to make a crawl-through castle, leave the ends of the boxes open.
choose two more boxes that are the same size. open their ends. they should then look like a square tube. let your kids jump and step 