Lookout

The Lookout is a building which was had been in disrepair until its rebuilding is suggested by Lord Davin. He wanted to use it for weather predictions, however the Guild saw the defensive uses of it and so agreed to rebuild it. Imardin's Guard use the Lookout as a prison for the most dangerous people.

Spoilers from "The Mad Apprentice"
The Record-Keeper of the Magician's Guild's office was located in the Lookout.

Spoilers from "The Ambassador's Mission"
Lorandra is locked up in the Lookout with her powers blocked.

Spoilers from "The Rogue"
Lilia is locked in the Lookout with her powers blocked, however Lorandra befriends her and gets her to try to break the block, using Black Magic. She passes the block and regains her powers. They then escape the Lookout.