Was easy enough to put together, but seems a little flimsy. But the problem is: it seems to be designed to appeal to the owner, not the pet. The way the levels are arranged, it's NOT easy or natural for ANY of our five cats to climb on. And they can't jump down to the bottom because there's a big hole in the middle. I greatly regret buying this, as the five cats have no interest in it, and it's easy to see why.