In Tibetan Buddhism there is a type of person called a Terton. They discover ancient texts which were hidden away to avoid some catastrophe, persecution, whatever. These texts are added to monastery libraries.
In the popular versions of Medieval monastery libraries (think Name of the Rose) there is a hidden section where heretical texts are kept.
I want to start to compile a long list of "lost" texts - crazy Pandaren monks' scribblings, early scientific treatises on forbidden topics, etc.
So I'd like all of your help - suggest a title, or a one sentence description of the subject if you can't think of a name. It's ok for them to be silly or wildly non-canonical. * Here's an example:
"Caves of Kun-Lai" - description of an underground Grummle city larger than Ironforge from which they manipulate world history.
You needn't try to create a fully worked out idea. I just need some sparks to fire up my own imagination.
* a cloistered monk's version of something a Wanderer told him about the outside world when the Turtle came back to Pandaria during Liu Lang's lifetime; transcribed, ellided & compiled centuries later, ...