From PathfinderWiki

Terapasillion (which means "Ziggurat of Night" in the Shadowtongue) is an ancient step pyramid eternally cloaked in shadows that predates Taldan settlement in the region, and is located on the northwestern plains of Cheliax near Nidal. It is rumored to have been built by shadow giants during the Age of Darkness, but was more recently inhabited by an umbral dragon. Despite the fact that the dragon has not been seen in decades, locals still avoid the place with a passion.1


  1. Amanda Hamon, et al. “Adventures in Cheliax” in Cheliax, The Infernal Empire, 38. Paizo Inc., 2015