From WoWWiki

The Hall of Mysteries is the center of arcane and divine power in the dwarven kingdom of Ironforge. It houses several mage, paladin, and priest trainers and a few quest givers.

Subzones of Ironforge
The Commons • The Gates of Ironforge • The Great Forge • The Forlorn Cavern • Hall of Arms • Hall of Explorers • Hall of Mysteries • Hall of Thanes • The High Seat • The Library • The Military Ward • The Mystic Ward • Tinker Town • Vault of Ironforge