Lukey and Riley have one from this site - the De Luxe Bastion. It was a bit more expensive than other similar height ones from elsewhere but it's handmade, the posts are solid wood instead of cardboard tubes so it will last much longer and as an added bonus it's not covered in gaudy pawprints
http://www.catscratcher.com/scratchers.htmlHere it is in action - it's used on a daily basis for sleeping, resting, play fighting, scratching etc etc
Not so active sleeping at the top...
The middle platform
The swing ball...
Now they've grown it's not quite big enough for them both to sleep (comfortably) on the top platform but that doesn't stop them trying!
The tunnel containing a full grown Riley (he is a very big boy too!)