Secret passageway! Cute idea if your house is designed properly. I remember a family friend's house had a hidden play room under their stairs. To get in, we crawled through a little door in their coat closet. Way fun for kids!
secret bookshelf door. I used to have a door like this at my apartment at sixteenth and Granville in Vancouver ! It had was a door to a closet that was the full tenth of the room and came out in the next room!
Secret passage (a "must have" in my home, if money was not an issue...) ^__^ Vm