The tiny dining room off our kitchen is the Cat Room. It didn't start out that this, and it's really all a matter of coincidence. We never intended to have a designated cat room, it just turned out that way.
We never really eat at the dining table, the room itself is super-tiny, and trying to fit more than a couple of people in there is a little silly. We do, however, feed the cats on the table, and although it is tiny, the dining room has two extremely sunny windows that are usually open. Evilcat's litterbox issues and pawprints on the table led to a few more additions.
The stools we keep under the table turned the tablecloth into a perfect place to hide. When the dogs decided to start raiding the litterbox, we put a tall babygate across the door and ended up with this:
It's a perfect dog-free cat habitat, complete with food, water, litterbox, places to hide, and sunbeams. Someday I'm going to add some shelves so they can climb/fall a bit. Yes, the dining room also has a doorway with a rounded top. It is way too cute. (When I'm outside I like to poke the cats through the window screen.)