In the Creation War, a primordial named Thyrm came to an area of Ice Cap that he named Netheram. In this area he set out to build a palace and a ring of fortifications. He thought that if the primordial invasion of Bal-Kriav failed, he would fall back to Netheram and hole up in Netheram. He created blueprints imbued with magic that were 10' wide and 20' long. Looking into certain areas would allow the viewer to drill down into other blueprints, so that one large blueprint would give access to a theoretically endless series of blueprints. In time, Thyrms Blueprints became tainted from chaotic energies or perhaps a flux in the Web of Magic and they took on a life of their own. When someone comes into possession of Thyrms Blueprints, they don't reveal what was done at Netheram, but other possibilities, grandiose construction efforts requiring the toil of thousands and sometimes centuries of effort.
Centuries later, the blueprints ended up in the dark reaches under Khalas. In the region Badmaer, the inspiration, or some may think insanity, for building Arakkhalgam was because of Thyrms Blueprints.
There are other places that would make one think that their builders fell upon Thyrms Blueprints. The first is Krarthjar. This fire giant hold in Krarthjar is of such scale that it could never have been full garrisoned, except by all the soldiers of a large empire. The other is a maze beneath the Eastern Shar called the Apex Maze. The tunnels of this place cover no less than twenty square miles and are still being worked on today. Many of Nevicanad's, the architect of the maze, diaries have references to an "accursed blueprint".