At first sight, most would think it was completely obvious what the man was doing. He must be building a pool, of course! It's the right size and shape, and what else could he possibly be doing?
Well, no. That's not what was going on here. Upon closer inspection you'd notice that he had filled the bottom of the gaping hole with course gravel.
The next step in his insane project would require a 20-foot shipping container be dropped off in his yard.