From the notes of Nikan shrubcover, concerning Zaphon’s tower and darkness

There is an ancient legend of a gigantic volcanic mountain that existed somewhere in the distant north during the mythological past. Our earliest histories speak of this mountain, which they simply call Darkness, as a gateway to the abyss and the stronghold of an ancient enemy who was so powerful and terrifying that I have yet to find a single ancient source willing to refer to it by name. In every ancient text that I have ever read, this creature was simply called “The Enemy.” There are some who claim that Zaphon’s tower sits on the site of Darkness due in part to the dark volcanic stones from which it seems to be built. I have no idea whether this is true, but one thing is certain, the stones that form Zaphon’s tower do not come from the Pillars of Heaven or even the Lunar Mounds as some have argued.