Hidden room, with a subtle if not disguised door. Need not be that big; never know when it'll come in handy. Even a small cabinet sized space may be useful. De

Hidden room, with a subtle if not disguised door. Need not be that big; never know when it'll come in handy. Even a small cabinet sized space may be useful. Depending on how much work you want to put into things all sorts of things may be doable. Fancy stairwell with a fireman's pole is probably a bit ambitious. Stone altar / sacrifice pit with plumbing and chimney can make a wonderful center to a den / conversation area room. Cook hot dogs or heretics with the neighbors.