There was a time when someone who had something of great value would often bury their treasure so that no one could find it and take it away. Of course, there was always the risk that one might forget where their treasure was buried, so to make sure that they would remember where it was, they would often make a map like this one. Usually they would mark the spot where the treasure was with an “X” like the one on this map. That is where we get the expression, “X marks the spot.”