mental_floss has another fantastic list up, this one about lost treasures. Lost in the very real sense of being still lost, waiting for you to find them. Like this one:
In 1820, a mysterious stranger left a locked iron box with Robert Morriss, an innkeeper in Bedford County, Virginia. The stranger, who went by the name Thomas Jefferson Beale, said that a man would be coming to retrieve the box some time in the next ten years. However, if no one ever came, Morriss could keep the box and the contents inside.
But what was inside the box? Beale reluctantly revealed that there were three pages covered in numbers. These “ciphertexts” were coded messages that could only be read by using corresponding documents as a key. Beale promised to send the three keys to Morriss when he arrived in St. Louis, so that, should the box become Morriss’, he could decipher the messages and learn the location of a treasure Beale had buried nearby.
The code above is part of the actual cipher. Like all members of my species, I think mysteries are sublime.
6 Lost Treasures Waiting to Be Found [mental_floss]