Halls of Stone

Halls of Stone is a 5-man wing of Ulduar in the Storm Peaks. The entrance is located in the southern part of the titan city by going west until you see the gate. It has a lot of lore closely tied to it. This is one of the non-linear instances in Wrath of the Lich King. The scale of the instance is large, with tall halls and rooms, but is still small enough to move about in without a mount.

From the official site
''The reasons for Loken's treachery and the fate of the other guardians remain a mystery, but there have been whispers of a great evil at work behind the fall of the titan city. For any heroes brave enough to seek out the truth, it lies within the corridors of the ancient compound. Thus far, however, few have braved the perils of Ulduar and returned to tell of their discoveries.''

Dungeon Journal
''Upon departing Azeroth, the titans entrusted loyal protectors with safeguarding Ulduar, an enigmatic city nestled in the mountains of the Storm Peaks. Designated supreme among his brethren was the guardian known as Loken, but with the power of the titan complex in his hands, he turned to darkness and plunged the region into chaos.''

Dungeon denizens



 * Air elementals
 * Beetles (critters)
 * Colossi
 * Dwarf (one, Brann Bronzebeard)
 * Earthen
 * Iron golems
 * Iron dwarves
 * Iron giants
 * Iron vrykul (one, Sjonnir the Ironshaper)
 * Oozes and oozelings
 * Rats (critters)
 * Titan (one, Maiden of Grief)
 * Troggs

Bosses
The order of bosses is non-linear, so the order below doesn't necessarily represent the encounter order.
 * Tribunal of Ages
 * Maiden of Grief
 * Krystallus
 * Sjonnir the Ironshaper

Achievements

 * Halls of Stone (achievement)
 * Heroic: Halls of Stone
 * Heroic: Halls of Stone Guild Run
 * Abuse the Ooze
 * Brann Spankin' New
 * Good Grief

Quests
Kaldir Ironbane offers two quests just inside the instance. There is also an escort event involving Brann Bronzebeard, that also rewards you with a rare item. Completion of this event unlocks the door to Sjonnir the Ironshaper. Note that you start the quest and can hurry him along by talking to him.


 * Corrupt Constructs
 * The Forlorn Watcher
 * Halls of Stone (quest)