The Successor State of Shenmen in central Tian Xia is a land of constant rain, interspersed with occasional storms. During the time of Imperial Lung Wa it was used as a dumping ground for unwanted or disgraced politicians and bureaucrats who were simply told to keep the lumber from the Spectrewood and the silver from the Gossamer Mountains flowing.
Once the empire collapsed, the land was quickly overtaken by monsters. Evil fey in the forests, cursed bandits in the foothills, and all kinds of ghosts and spirits in the waters. The worst are the spider-creatures known as the jorogumos, who now rule the land from their underground capital of Yin-Sichasi and other cavernous homes across the Gossamer Mountains.