Had just a few bits and pieces of lumber that didn't fit in with any of my other plans. My cats were bored (and getting into trouble because of it). I realized they didn't have any play structures of their own in the house. Menards had some runner rugs on sale for $6 each, so I used two and chopped them up, then stapled them into place. I might get 2 more to finish it all off nicely. I admit I didn't make the gray thing that's in there with the holes, but it was a gift from DH's folks a long time ago. We didn't let the cats use it since the biggest of our cats was constantly pulling it over on himself (ironically he's not in the pic... he's off lazing somewhere else currently). So now it's secured into this "playhouse", and they love the whole thing. Took me about 3 hours to do. All of the legs are bolted through the bottom of the big, heavy piece of plywood too. Nothing's going anywhere.