You've probably seen an arrangement like this at certain shopping centers (this one's near a grocery store), or you might even have or have had one where you live. What is it? And why is that key in the lower-right just hanging there?
Each of these things is a collection of mailboxes called a cluster box unit. There are three CBUs in this photo, and they have a couple of neat features that I want to highlight.
the suburban neighborhood where I grew up had these; I basically walked ~10 minutes to the end of the street to pick up the day's mail in big boxes exactly like this one, except painted red and blue to match the canada post colors

