The room is in four spaces. The first space on the left is the telescope/potion bottle area. The base is 5/8 inch plywood. The walls are 1/2 inch foam board insulation. I love to work with this. Then I drilled holes along the left edge and back of the board. Into the holes I put two inch pointed sticks . I glued two pieces of foam board together; the inside board is 1/2 inch shorter than the outside board, so the lid can fit in the top. I then made the back wall: two pieces of foam board, with a narrow third piece in the middle. I put stone floor wallpaper from miniatures.com. It looks great. I made shelves to put the potion bottles on. The backing is wood floor wallpaper from Itsy Bittsy. I also used it to cover the floor of the telescope room. That's it for now. Will post more later !!