I have a cat tunnel, and the cats love it. It's a
the Day on Amazon for $11.79
(Reg $29.99). Be sure to look at all the pictures. You can hook more than one
together to make a maze. It compacts almost flat for storage. Comes in beige,
brown, or gray. Ships free with Prime, or free on $35.
When I have foster kittens, they go nuts chasing each other through it, and
doing ambushes out of the center hole.