Orzammar Proving, in the room south of the main-hall. This room will not be accessible until you progress beyond a certain point in the quest lines to prove yourself to Bhelen or Harrowmont. Writ of Censure.
Finding the first scroll creates a note in the codex, in the "Quest Related" section. Once all scrolls have been read the Warden will receive the quest and a chest will appear in the Chamber of the Assembly in the Diamond Quarter. It contains the item.
Key to the CityKey to the CityRing Key to the city of Orzammar: A traditional diplomatic boon, granted by the Assembly, in acknowledgement of the bearer's understanding of the complex dwarven social weave.
+2 to all attributes +4% spell resistance +10% to healing effects received, a ring which boosts all attributes by two, gives a boost to spell resistance and healing effects received. However, note the +X% to Healing Effects Received bug here: Bugs (Origins)