The Motte & Bailey Tower at Vargas was originally designed as a storehouse of information, predating Crestfallen Library by some 400 years. In it's day, travelers came to seek the council of the sage - Miros Chanel, and spend time searching the large (for it's time) 800 book collection.
Miros designed the layout based on an early M&B South of Yggsburgh, adding in a few surprises and secrets of his own. The sub-level gave direct access to the dungeons, and another large collection of books, although the proper magic to open the doorway has long since been forgotten.
Presented below is the M&B Tower complex, with levels and furnishings: