Pathfinder - Second Darkness
The Gas Forges are located in the Wharf District of Riddleport. They are an extremely large structure of brick and iron with dozens of chimneys. The structure is populated by dwarven laborers who put on crude breathing masks as they work. Riddleport sits above a large deposit of carbauxine, a rare gas normally found deep in the Darklands. Carbauxine is a poisonous, heavier-than-air gas that is difficult to work with, but carbauxine forges are immensely valuable in metal-crafting. The Gas Forges are the only forges in Varisia capable of smelting adamantine and other high-hardness metals.
The forges are owned by an anonymous consortium of dwarves that live in Janderhoff. They trust the daily running of the Gas Forges to Tromard Roldheim.