Any sort of item that conceals a 'hidden space'

My business 'Hidden Agenda' deals in merchandise that conceals 'locked safes' and hidden space. Presently, my company sells only one product, a large faux garden rock with compartment. I would like to branch out and produce more products. Any ideas would be welcome. An idea I want produced is a box with faux grass on top which would be berried in the lawn. the top of the box would lift up revealing a compartment.