Our mario compex comes complete with portals that are lined with sisal, so the kitties can climb in and out of the blocks. The blocks are all attached and have a tunnel that allows climbing from one portal to another.
The boxes themselves are all 11.5″x11.5″x9″ oak ply. All of the wood has been cut at a 45 degree angle to give the boxes a seamless look.
The complex is attached to the wall in such a way that it appears to be floating. The blocks are all separately equipped with brackets that attach the top of each block to the wall like a shelf. The weight of the block itself with your kitty inside of it holds the box firmly in place. These brackets are designed to be aligned with studs in a typical wall at 16″ apart .
While the frames of the boxes are all solidly built, the brick face plates are detachable to ease installation of your complex… or in case you get jealous of how much fun your kitty is having and want him to spend time with you again.