I appreciate everyone's comments - at least I know I'm not alone in this! An update from my original post: This is an ammo container (so animals can't move it). I asked the last finder details on where it was found, and it wasn't just laying in the open - it was actually placed on the blocks surrounding the hedge! Not only in the open, but placed so attention would be drawn to it!!!
By the way, the comments about migration are absolutely correct. It looks like people don't want to stretch to put it back, so it ends up a foot or two away from the original spot. Then the next person moves it again until it ends up quite far from where it's supposed to be.
Happy caching everyone! Thanks again for the comments.