The Voynich Manuscript
The Voynich manuscript is an ancient book that has thwarted all attempts at deciphering its contents. It is actually an organized book with a consistent script, discernible organization and detailed illustrations.
It appears to be a real language--just one that nobody has seen before. And it really does appear to mean something. But nobody knows what.
The manuscript contains an illustrated codex hand-written in an unknown writing system. The vellum in the book pages has been carbon-dated to the early 15th century (1404–1438), and may have been composed in Northern Italy during the Italian Renaissance. The manuscript is named after Wilfrid Voynich, a Polish book dealer who purchased it in 1912.
The manuscript has been studied by many professional and amateur cryptographers, including American and British codebreakers from both World War I and World War II. No one has yet succeeded in deciphering the text, and it has become a famous case in the history of cryptography.