Sorry the op got robbed by thieving scum bags. Had a friend in a similar situation, meaning valuables locked up on remote property and we came up with the idea of setting up an owl box high on a tree and include a solar panel and hidden camera as one point of surveillance, but never set it up because his situation changed and he sold the property not long afterward. Another thing we did do was mount small, inconspicuous cameras in his storage container to identify who and what in the event of a break in. Another thing we did was securely attach
small but noisy piezo alarms (there are a lot of options) to easily moveable stuff that have a trigger that gets pulled out (attached to fishing line) to activate the alarm. We also wired up additional alarms that triggered if a door was opened. It wouldn’t stop anyone, but adds to their confusion and time trying to quiet the alarms. These days I would also place Apple tags in or on things making them trackable. My other take away from the op is to always check thoroughly the surrounding area for stuff that was stashed, something I hadn’t thought about.
