In the past when the Maggi Republic existed, there was a plastic one but it doesn’t matter to felines, they have to climb it. After coming home from work, only to find it on the floor half the time…well, that was the end. I do recall one evening waking up from my television-induced nap by Nemo “cursing.” He was stuck on a mid-level branch. With Isis and Agamemnon, I have no clue yet I’m not going to chance it with the latter cat, he just have mischief written all over his cute face.