This view is at the under ground entrance to a large wine cellar. You can just see an arched inset in the stone wall.|
The homeowner asked me to "do something far-out and funky here". So, within this area, I built a hidden recess behind one of these stones to hide the key to the door
that enters the wine cellar.
I attached a steel rod, off center, to the back of the "secret" stone. The rod slides in and out of a steel sleeve that I embedded into
the wall behind the stones. You pull the stone out, rotate it down out of the way, and a light comes on inside the secret compartment behind where the stone was,
revealing the key to the door.
You would never find it by tapping the stones as the secret stone is eight inches thick and fits tight when in place.
Here's looking in the other direction from inside the cellar door.
Here's the area above the cellar.