The Prime Roots make up the most mysterious ecosystem on Atys. Delving into the bowels of the planet, this never-ending labyrinth of deep caverns can astound the curious eye with its remarkable beauty, blinding them to the danger that also lurks within. Sap flows here in endless rivers and fluorescent plants softly light the way for travelers, while strange creatures prowl about in the shadows. The Prime Roots are home to a host of mysterious relics from the past as well as a wide range of resources that can found nowhere else.

The Prime Roots are subject to only slight variations on climate, remaining cool and damp year round, but always dark. Due to this unusual climate, much of the flora native to the Prime Roots has developed the capacity to generat its own light, creating an environment both fantastic and alien.

It is here that Fyros excavators first came upon a nest of Kitin, sparking the great war that devastated all civilization many generations ago. This memory still haunts the Homins and they avoid settling near the passages that lead to this dark place.