I have two cats and they both love it!  It is very sturdy and isn't so large that it takes up too much space in my apartment. I have a big male cat that is 17lbs, and he fits just fine with plenty of room in the bottom house, and it's super sturdy no matter where he climbs on it! Definitely a great purchase! The only reason I give it 4 stars is that the hanging toy that comes with it seemed to be very dangerous. My 4 month kitten got it wrapped around her paw because the string is elastic. She is fine but I recommend if you have a young playfull cat don't hang the toy! Other than that great tower!