I just discovered Kuranda now has cat towers. Towers come in heights from 2 to 9 perch levels to fit your area and maximize floor space. The tower is designed with more weight at the bottom to keep it secure from tipping. But what's really important (to me) is the PVC frame and solid vinyl fabric is non-porous and can be fully sanitized with bleach or disinfectant. Petfinder members get a discount but still...I'll have to save my pennies so I can buy one or two for my fosters. Obviously, I want the 9 perch tower. Simply sublime.