Voynich Manuscript: A weird and unreadable book
The majority of the book contains images of biological specimens, astrological diagrams, and strangely enough nude woman bathing in a complex system of pool and pipes. While it may not be quite as weird as the Codex Seraphinianus, it is definitely a very strange book.
The book was discovered in 1912 but recently popped back up into the news this week after the University of Arizona finished carbon dating the original copy as having been written between 1404 and 1483. Despite the work of many cryptographers over the past 80 or so years the book remains un-deciphered to this day.
If you want to learn more about The Voynich Manuscript there have been some recent publications looking into its mysteries which can be found for about $20.