The history of secret doors in medieval structures like England's Warwick Castle also offer ideas for pieces other than bookcases to hide your door within. A secret door could sit behind paintings ...

We’re spotting hidden ... have a bookcase built into it, using invisible hinges to keep the door hidden on either side,' says Emma Deterding, founder and creative director, Kelling Designs.

We have a pretty good guess where [Krizbleen] hides away any seasonal presents for his family: behind his shiny new secret ... door as necessary, onto which [Krizbleen] expertly mounted the ...