One of the lesser-known mysteries of London, England, is tucked away between the Tower of London and St. Paul’s Cathedral. At 111 Canon Street, inside a WHSmith (a British book retailer and, incidentally, the inventor of the ISBN catalogue system) behind a protective grille sits the London Stone. No one knows the purpose or significance of the Stone other than the one imposed upon it by generations of Londoners and writers. Many have mentioned it over the last 900 years as a significant object for London’s history, but no clue remains as to its origins. In a sense, it is historically important because people have made it so.