Garden Tool Storage Box Security?

I have just purchased a new garden tool storage box which is fairly expensive. Because my garden area is open (communal) I am worried in case my storage box goes "walking". Any ideas how to secure the box so that it cannot easily be taken?

 

Get hold of a corporation type paving slab, drill holes in each corner of the box. Sit the box on top of the slab and mark the four holes through the box on the slab. Then with a masonry drill, drill the four holes in the slab. Put in the four polyplugs for screws. Buy some really wide washers like a couple of inches in diameter. Then screw the box through the washers to the slab.
No one will be able to lift it.