Very nice looking, I have two cats, one old, one younger. Younger one is  too big for shelves but can get in and out of the whole if the dog and older cat are not around, if they are he stays put until they disappear. Older cat has claimed it has hers. My pets to not share very well.
 

Pros: Easy to assemble
Cons: Do not recommend for larger cats (15# or more)