The 5 nest cat tower was easy to assemble but I took my time and paid careful attention to each step. At first all the legs (two of the six) wouldn't sit evenly on an uncarpeted surface (minus one star) but I used rubber leg tips (available at hardware stores) inside the tubing to increase the height of the two "short" legs. I added washable fleece pads to each nest (tying the pads to the frame with string which the cats love to play with). Within two days all 5 of my cats began to try out the various positions. The cats use the tower a lot more than I had even expected when I ordered it.