A safe on its own is a heavy box with a handle. What makes it secure is the fixing: bolts from inside the safe into something solid, so that it cannot be lifted, levered or carried out while you are away. In most houses that solid thing is a concrete floor or a brick or block wall, and the fixings are chosen to suit them.
A cave house in Crevillent asks a different question.
What a cave wall is
The cave houses of the Coves have one built wall, the front, and rooms dug back into the slope of the ravine behind it. The back walls are not built: they are the hill itself, cut and finished, often plastered and painted so that you would not know from inside. An architectural study of Crevillent’s caves divides them into four building types, so no two are quite the same.
That has two consequences for a safe:
- You cannot assume what is behind the plaster. The material of the hill can vary from one cave to the next and even from one wall to the next, and a fixing that holds well in one may hold poorly in another.
- Drilling into it is not the same as drilling into brick. The hole, the anchor and the depth all depend on what the drill finds.
So, wall or floor?
Before anything is drilled, the wall and the floor are both looked at:
- A floor slab is usually the first choice. If the cave has a concrete floor, a floor fixing is often the simplest strong option, wherever the walls are dug.
- A built wall is the second. The front wall, or any partition built of brick or block, behaves like any other masonry wall.
- An excavated wall is considered last, and only after the material has been tested with a small pilot hole, with an anchor suited to what is found.
A safe can also go into a fitted cupboard, provided it is fixed through the cupboard into the floor or wall behind it, not just into the cupboard.
Where in the cave
Out of sight, but not in the obvious place: the bedroom wardrobe is the first place anyone looks. Avoid damp corners, which are not kind to an electronic keypad, and leave room to open the door fully.
If you are restoring a cave
If a cave is being restored, the best moment to plan a safe is before the floor is laid, when a fixing point can be planned into it. The same goes for the front door and its locks; the cave house page covers those, and the guide to what sits behind the front door explains how the caves are made.
For a business, the logic is the same but simpler: on an industrial estate the floor is almost always concrete. See the guide to keeping a unit secure over the weekend.