Invariably, if you buy an expensive cat bed or a cat tree, and the cat prefers to play with the cardboard box. So why not let your cat lead the way? Take those excess cardboard boxes and create something personal and fun for your cat! Cardboard is a wonderful building material. You can cut it easily where you need to, bend it to your will, and tape, staple or glue components together as you see fit. It can be decorated with paint or signage or whatever you have laying around. You can arrange it in a maze to give your cats something to explore, make it into several rooms so they can select their own favorite spot, and stack boxes atop one another to give them climbing fun. Then give it a funny name so your photos can go viral on the internet, like redditor Teharu did with the fort pictured above. It went viral enough to be featured at The Irish News, where you can see more pictures of it.
Half-Asleep Chris built this lovely fort for his cat Ralph, and then posted a video on how he did it. But it's not entirely cardboard- it has a wooden frame. He later built another, bigger one for two cats, and used "cardboard bricks." This video shows that process that resulted in Boxingham Palace.
I'm impressed. But you don't have to go all out to have a fun and creative cat fort. All you really need are cardboard boxes and some imagination. And some gorilla tape would be helpful. See more cat fort designs for inspiration in this photo gallery.