Build a Secret Spy Bookcase

Building a secret spy bookcase is not as difficult as it may sound. Who wouldn't want a secret lair all to themselves? Learn how to make your own.

Instructables member nylanan provides simple plans for  a hidden door. Check it out:

Another example from flickr member agmk (unfortunately no instructions posted). Hack N Mod explains, "This door is dirt simple to create. It's literally just a bookcase put on standard door hinges with coasters added to the bottom. "

Image Credit.