secret door to an underground storm shelter/panic room/hid out in the kitchen island! Best secret passage ever! Definitely a dream home feature! (would also be good if someone broke into your house and you had to hide somewhere) Zombie apocalypse.
Your standard bookcase-as-door secret room There’s added personality injected into a space when you’ve got a secret door or secret room. And it helps if that door doubles as a place to keep your books, too.
The hammock is a great idea so smaller "secret playroom" areas. This kid’s bookshelf opens to a secret reading nook. A SECRET READING NOOK. I would’ve never left. (from Everything About Secret Bookcase Doors)
A secret storage in a staircase can be a great hidden storage for bulky things that look unflattering when stored in full display. It’s the same space under stairs only hidden and accessed from the floor in the staircase. At: The Bottom Of The Stairs