Brennenburg Castle

Brennenburg Castle is the main setting of Amnesia: The Dark Descent, acting as a gloomy castle wedged in the forests near Altstadt, and was rebuilt by Alexander of Brennenburg in the 16th century.

History
The castle was first built in the middle ages where it was destroyed by a fire and was rebuilt by the aforementioned Alexander, an interdimensional being who made the castle his mansion. Alexander used his castle as harvesting grounds for Vitae, a mystical substance that extends a user's lifespan and found in the blood of animals and humans that could only be obtained through torture. One his helpers for the torture was Daniel, a young English archaeologist who was carefully manipulated by Alexander into violently torturing several people.

Daniel grew more and wearier the more people he tortured but was reassured by Alexander that he was only torturing criminals who deserved it. Daniel finally gave up after murdering a little girl, knowing for sure she couldn't have been a criminal and Alexander had tricked him. He then drugged himself with an Amnesia potion to forget the torture sessions and left himself a note to kill Alexander for his crimes, setting up the events of the game where Daniel attempts to do so. In his attempted assassinated, he is stalked and hunted down by the castle's deformed guards, The Gatherers, as well as the dreaded Shadow.

Archives
The archives serve as a vast library where books and other records are stored and is visited by Daniel solely in his search for the key to the Wine Cellar.

Wine Cellar
The wine cellar is where chemicals are stored, and is possibly the origin of the Gatherers as the deformed remains of Wilhelm and his men laid splattered around the cellar after they were poisoned by Alexander. Daniel visits this cellar to given some mixing chemicals, and this room marks the first appearance of the Servant Grunt, albeit just a visual.