Dunwall Tower.
The Tower of Dunwall is a book found in Dishonored.
Transcript
[Excerpt on a historical examination of Dunwall Tower]
For over a century, Dunwall Tower has been the capital of the Isle of Gristol, and the seat of power across all the Isles of the Empire.
Rulers have come and gone, each adding something to the structure. Gardens, observatories, new walls, pools and specialized interior chambers to suit their needs and whims. Dunwall Tower has withstood numerous wars, several large-scale fires and the collapse and rebuilding of the northern wing.
With Tyvia and Serkonos joining the Empire first, it was Morley that resisted longest. Some of the conflicts that arise also necessitate the further fortification of the Tower. Repeated assassination attempts, near the end of the conflict with Morley, resulted in the creation of the Royal Protector position, with each ruler choosing his or her own Royal Protector after careful consideration.
Location
This book can be found in the library on the second floor of Dunwall Tower, right outside Hiram Burrows' chambers during the mission, Return to the Tower.