I love old houses. I like the idea of hidden rooms and secret passages. (Spider and spector free, thank you very much)
Mostly I like the cleverness of it all.
Recently there's been a return to some of these things, mostly for hiding storage areas and the like - but they are worth mentioning. Check out these pictures!
They also have vendors that make stairs that lift and more. Here's a couple links to some crazy inventive passageway ideas:
You may never need a hiding place, like Anne Frank, but it sure wouldn't hurt to be prepared, right?