Bunk Bed is a 2x3x4 box with a hinged lid and 1x4 openings in the long sides. The goal is to put six pieces in the box. The flat pieces can get through the openings...Show more of the box quite easily. But the 3D pieces need a lot of space and use of the hinged part to get in. Once they're in, there's little room left for the flat pieces. In short, packing the bunk bed is a puzzle!