Cat shelves or cat walls? No matter what you call them they are the coolest diy cat idea I've ever seen. Cat climbing shelves are a great way to make something cool for you cats & save space in your home.
Litterbox cabinet - SUCH A GOOD IDEA! Give the cats their own little litter box cubby room. It gives them their privacy and you can contain any mess on the outside of the litter box and easily clean it up.