previous pinner - My husband built this for our boys. We call it an indoor tree house. Its a fun thing to play on and around. Our older son loves climbing up and sliding down. The slide also doubles as a dresser.
I like the idea of making a ramp to encourage the use of their back claws. We may have to make it a little lower for our cats, but it still seems like a great way to encourage exercise. I could attach it to a bookcase