The Thair Mountains are a mountain range that forms the border between the SouthLands and Arin, and stretching from its western foothills in Lan-Zarek nearly to the Golden Ocean. Its principal inhabitants are the dwarves of Thorin's clan and their allies, the humans of the city of Braith, and within it lies at least one entrance to the UnderWorld.
These mountains served as one of the key battlefronts during the Wars of Arin. The forces of the Onyx Empire tried on many occasions to find a safe pass through the mountains and into Kellan, but were always turned back by its defenders and eventually had to bring their armies all the way around into the western foothills. Even today, there is no known pass that leads all the way through the Thair except through Braith.
Like many of their kind, the Dwarves of the Thair Mountains are miners. The mines within the range provide much of the metallic ores used throughout the SouthLands.