Dragon Age - Thedas

The Deep Roads once linked the thaigs with one another and to the surface. These subterranean highways were works of unparalleled artisan achievement, with centuries of planning and engineering demonstrated in the geometry of their walls. Statues of the Paragons watched over passing travelers, and channels carried a flow of magma that kept the Deep Roads lit and warm. The Deep Roads have long been taken over by The Darkspawn becoming their home. The vast majority of Darkspawn are down here except during a Blight. No one knows just how many Darkspawn are down here According to Bianca Davri the Deep Roads may even extend further than the continent of Thedas