This kitty mansion is very sturdy and most importantly the cats love it! They run up and down the thing, lay on the different seats and hide in the houses. It took 2 hours for us to put the thing together. The instruction included one piece of paper with one diagram. There are no written instructions, so you have to plan ahead and think out how to put it together beforehand. The only tricky part was getting the pieces that hold the hammocks in. We didn't put the leaves on the tree because the cats chewed them up before we even got the tree together. Overrall, this is the sturdiest cat tree we've come across though and the kitties are getting a lot of use from it.