Have you guys ever heard of the Voynich manuscript? I just saw an article about it; before today I'd never heard of it. Owned by Yale University, the Voynich manuscript is a handwritten, heavily illustrated book from the 1400s, whose author, subject matter and language are all unknown. I am utterly fascinated by this. Here are scans of the manuscript from the Yale Library.

Edited to change my hyperlink to point elsewhere - evidently mah blog is so powerful that I crashed the Yale Library. (I had previously linked to scans of all the pages - they are on Flickr as well).