The Dark Bargain
Unlike in most worlds, the Dwarves in Kallan do not live primarily underground. In Kallan, the Monsters that live underground are even more terrifying than the ones that live above it. The Dwarves serve as a divinely-appointed military to defend the mortal world from the endless onslaught of Aberrations from below and the Bloodthirsty Giants to the West. The Gods created the Iron Peaks live in as a natural barrier, but the Giants still tried to get through, so the Dwarves were relocated to better protect the others.
The Dwarves live in enormous cities made mostly of Iron, which is abundant in those mountains. These giant fortresses often block off entire passes and are well designed for sieges. The Dwarves trade heavily with the other races for the food they cannot grow or hunt in the mountains. They are master craftsmen and their trade shows it. In places where the Aberrations are coming close to breaking through, they will create tunnels into the Mountain to better control the flow of monsters and the battles that follow.