Hidden storage rooms

When I was younger, I loved films about grand old houses, all of which seemed to have a magic door set invisibly into the wall somewhere. The glamourous lady of the house, whilst fleeing whatever was chasing her, would pull on a book in a bookcase and the secret entrance would whoosh open, revealing the hidden room. These days the concept is still used and although I sadly don't have that many valuables that need to be secreted away, I still crave one of these for the study.

Images from Busyboo, Apartment Therapy and Heartfire at home.