The Voynich Manuscript

The Voynich Manuscript, aka "The World's Most Mysterious Manuscript," is named after the book dealer who acquired it in 1912, but nothing is known of it's true origin or author.  It's thought to have been written sometime in the early 15th century, and it's basically 240 pages of writing and illustrations divided into six sections: Herbal, Astronomical, Biological, Cosmological, Pharmaceutical, and Recipes. 

What's amazing is that it was written in an unknown language, and so far no one has been able to decipher the text, though it's been studied by many professional cryptographers and codebreakers.  The letters, which sometimes look similar to Roman and Latin glyphs and sometimes look completely different from any written language, are arranged in close formations like words, but appear in odd patterns.  Some letters appear only at the beginning, middle, or end of words, and common words are often repeated three times in a row.  It was written fluidly from left to right, and there are no obvious errors or corrections.

Another strange thing is that none of the plants can be identified.  Many of them are puzzling combinations of roots and leaves that wouldn't normally grow together.  

Based on the illustrations it's thought to be some kind of pharmacopoeia or medieval medicine guide.