I'm not sure why backwards pointing arrows are so rare - like these ones on a flight information display at Helsinki Airport.
If you don't know where something is, it is only by chance that you might be facing in the right direction when you look for it on a sign.
Usually it is the absence of an obvious destination that tells you it is not in the direction you are facing. So you have to turn around and look for it on another sign, or, in the case of a hanging sign, look on the other side to see if it is listed there.
