Skyrim: Dawnguard - Unknown Books
The locations to all 4 volumes of Unknown Books in The Elder Scrolls V: Danwguard DLC for Skyrim.
For the Emerald Paragon and Paragon Platform locations:
• Skyrim: Dawnguard - Paragon Locations
The Unknown Books are ancient tomes written in the Falmer language. Four books are scattered across the Forgotten Vale.
Each book can be sold to Urag gro-Shub in the College of Winterhold for 1000 gold and a translated version of that book.