Kal'Hirol

The dwarven fortress of Kal'Hirol was long known as a center of learning for the smith caste. Its workshops are where Paragon Hirol conceived his famous improvements to golem resilience and power, and where Hirol's favorite student developed a method for storing refined lyrium that is still used today. These breakthroughs brought Kal'Hirol great prosperity; its passageway are said to have glittered with gold and silver. But the fall of Kal'Hirol is shrouded in mystery. All that is known is that the fortress's elite one day showed up at Orzammar's great doors, exhausted and in despair over the loss of their home.

Source
Official BioWare page