High atop the Circle Tower, the Harrowing Chamber is used to conduct the Harrowing ritual to test apprentices mages who are ready to become full members of the Circle of Magi.
Magi Origin Edit
Dragon Age: Origins Edit
During the Mage Origin the protagonist undertakes their Harrowing here.
During the events of the Broken Circle quest, it is used by Uldred as the place where he turns captured mages into an "army" of abominations. The Warden enters the chamber and slays him.