I know that Torag told the dwarves, who were then living in the Darklands, to go up to the surface; this is described in a lot of sources. But I could not found yet at what layer of the Darklands they lived when they got the prophecy,
and in what area in the given layer they lived.
Can anyone clarify this for me?
The quest took about 300 years and started in Nar-Voth (Dwarves of Golarion, p. 17).
When the dwarves of Nar-Voth began their Quest for Sky, not all of their people were convinced of the wisdom of tunneling upward, and some steadfastly refused. As time went on and the questing dwarves moved farther toward the promised surface lands, they and the holdouts who remained behind grew further and further apart culturally, and, eventually, physically.
Surprising, I know. But we have only the faintest idea of how vast the Darklands are. Digging through the safest and closest area of the darklands took 300 years, and dwarves are skilled miners. Imagine how long it would take to dig from the deepest reaches of Orv.
According to Into the Darklands (which also describes that orcs and dwarves had kingdoms in Nar-Voth), Nar-Voth extends down to about 2,000 feet. Which means that the dwarves took their sweet time to get out of there. Of course, there weren't any natural tunnels until then, I believe, and they were the first to dig through all that.
The fall of the Starstone at the advent of the Age of Darkness changed the world of Golarion forever, and these changes were not limited to the surface world. The impact of the Starstone was felt throughout the Darklands—and the upper reaches of Nar-Voth in particular. Many caverns and passageways under what is now the Inner Sea were destroyed, along with a large portion of the underground orc empire. For unknown eons before this event, the orcs and the dwarves, two races that had vied for control of these caverns for as long as either could remember, ruled the caverns of Nar-Voth. Where the dwarves were masters of tactics and defense, the orcs were fecund and warlike. No matter how many orcs the dwarves slew, more grew up to replace those lost. And no matter how often the orcs assaulted the great dwarven city-fortresses, the dwarves always rebuilt.
According to Into the Darklands as well, the Duergar also took several old dwarven fortresses back, and the book shows us three of them:
Fellstrok and Hagegraf are both connected by the Long Walk, which is a major tunnel that serves as a trade route for several races in Nar-Voth.
