I was worried at first about the stability of this tree with my 13 pound, only 1 year old kitty. I wanted to find something that had a big platform on the top so he could lounge and not fall off. He is very active and likes to run and jump on and off if it, but has not knocked it over. He immediately loved this tree that I set up next to the window for him to bird watch. The string with toy didn't last more than about 10 seconds, he bit right through the string, but that was to be expected. He does not go into the cubby (middle) part, but he likes to hide his toys in there. Thanks for the great deal, affordable price and simple design that we were looking for.