This is a sign in front of a small riverside park. It says:
Superman: Oi, mate, whatcha doin’?
Superman: But this river supplies the water system. Fishing here will affect the quality of the drinking water. So please don’t fish here. Cherish the source of our drinking water!
No, I have no idea why the fisherman is a knight. Or why he’s fishing from the back of his horse. Or why the horse is wearing sunglasses. Or where Superman comes into it.
And I think the locals don’t get it either, because they keep fishing there anyway.