Quiz

Could you please highlight with a red circle where you saw the skulls? This completely ruins my hypothesis about a crypt for the thrifty.

Added 1 minute later

Like a protection against drunkenness? If you can't get the key into the lock => that's enough alcohol for today? ))

Something along those lines. And it's also a good protection against guests who come to grab a couple of bottles. Each bottle has its own key.