i did not realize that the middle "platform" is more like a hammock.
my cat is only 6 months old, but already too heavy for it.
i took it out & screwed the two poles together so my cat needs to climb 
a little further to get to the top platform.
the whole structure wobbles & needs to be bolted to a wall for stability.  

Pros: looks great, my cat likes to sit on the top platform
Cons: bad design.