Here's a picture I actually took myself. This is the back door to the large metal building in which my family live (in an apartment above the offices).
Yeah, the method of closing the door at night is medieval as fuck. The double doors have a latch on top of one door that hold it closed, and the left door's handle locks in to the other door. The way it's set up wasn't as secure as we would have liked when we installed it. If you jiggled and pushed hard enough it could open when locked. Solution? Well we got so steel strips, a blowtorch, and a 2x4. If you look closely the board strangely fits perfectly in the first "step" in the door frame.