We put a Camelot Cat Condo above this unfinished window (on the list) and our two cats loved sleeping and playing up high. The cats are geting close to full grown and there's really not enough room on top for both cats and they wake up and start whacking each other till one moves. Now with a third cat on the way we figured we would get the Sand Castle Lounger. The cats spent there first night up there yesterday. I'm going to finish off the rest of the window with Kitty Carpet because the cats seem to like destroying this window for some reason.