The Voynich Manuscript is an illustrated handwritten codex utilizing an undecipherable text. It was carbon dated from the early 1400s and might be of Italian Renaissance Era. A Polish book dealer bought it in 1912. Even though some pages are missing 240 remain.
It has been studied by some of the worlds best cryptographers and code breakers from the wars and they still cannot make heads nor tails of it.
To me, the script looks as if it's written for reading in a mirror - it seems almost reversed, but then no one really knows the origin of this "language."
To add to the mystery even more, it shows illustrations of sunflowers, which were not found in Italy in that time period. Some have come up with the theory that the manuscript was written by a secret order of people hoping to pass on knowledge. There many dozens of researchers who have spent decades a piece trying to decode this book with no strides. Some have come forward with possibilities, but are shot down by others. It may remain a mystery for all time, or it may just draw more people into its unsolvable riddle until they go nearly blind studying it.
Would you like to try you hand at the mystery? A high quality digitized copy is online here.