The Chronicles of Anglarthea - The Legend of the Sages Stone
The fabled lost Thaig of the dwarves. Theories surrounding it’s disappearance vary, however there is always one constant, the reason that dwarves can not use Arcane magic (or choose not to) is a direct result of this city “vanishing”. The most popular theory originated from the dwarven scholar Taldor Copperbeard in 370DR speculates that Dundathal dwarves were able to use arcane magic as well as or better than the elves. However the constant use of arcane magic and quest to be more powerful led to pacts with demon, it was during this dark time that the last great dwarven wizard, Boal Flamecaller, used his power to seal Dundathal, and the secrets to dwarven magic below The Vankardi Mountains.
This has never been proven, as Copperbeard was never able to organize an expedition.