If you find Argleton on your map and then visit to find nothing but a farmer’s field don’t be alarmed.
As Greg Ross noted on Futility Closet:
Danny Dorling, president of the Society of Cartographers, said, “I would bet that this is an innocent mistake. In other words, it was not intentionally inserted to catch out anyone infringing the map’s copyright, as some are saying. But the bottom line is that we don’t know what mapping companies do to protect their maps or to hide secret locations, as some are obligated to do.”