This secret door from HideADoor.com is made to look like a series of special purpose storage bins. The slanted shelves swing out to reveal whatever hidden room lies within.
This modern wood panel wall opens up to reveal a series of shelves, storage drawers and even a secret door. With a bit of planning, this could be replicated in many situations.
This DIY project featured on Design Sponge shows how to make a secret storage box that sits on a bookshelf and conceals it’s contents behind a painting.