This fence is known as “The Safest Wall” in Seoul, South Korea. Couples show their love for each other by locking a pair of padlocks to this fence, and throwing the keys over the edge.
This small, personal wooden stash box has been decorated on the inside with a collage of cutouts. This could be used to store any number of small items.
This driveway raises to reveal an automotive elevator to a secret garage below. This is really cool, but seems like it could be a pain if friends were parked in the driveway when you wanted to get the car out.
Here’s a pic from Tumblr of a feather stashed under a floorboard. While this is taken for art’s sake, it shows that there are possibilities for secret storage.