Every once in a while, we encounter a sign that makes us do a double take. Maybe it offers a strange piece of advice, or a curious directive. Maybe it forbids something we can't imagine a human being actually trying. But in every case, we have to wonder: How did it become necessary to put this up?
Imgur user chocolateistheanswer has compiled a wonderful collection of such signs, and they are each a sight to behold. Join us in puzzling over their origins—or, if you know how they came to be posted, please tell us, because the mystery is driving us mad.