Gunul-Birum is a small volcano at the base of the Zurukthûr depression. It came about from a rift created between Chaos and this area. This happened in the God Era when the revived disembodied thinker Ingu'lumin pushed an entire mountain through Ingu'lumin's First Rift. This mountain was then bored out with fiery entropic matter and fed by one of Chaos's innumerable, free-flowing lava streams. This conduit, feeding alien matter in the form of lava, creating an artificial volcano, did not last. Weave Spiders, guardians and maintainers of the Web, were quick to fix the damage. Weave spiders, uncomfortable and unable to last long outside the Web of Magic, could do little about two halves of a mountain infused with entropic energy. In the process of closing this rift, the spiders killed three clones of Ingu'lumin. These clones were under tight psychic controls, surgically enhanced. Their primary mission was to keep the rift open as long as possible. They did not flee under attack, instead following their secondary purpose. This to observe the Web's guardians, probing for habits, limits, behavior, and weaknesses.
A few months after closing of the rift, the second stage of Ingu'lumin's plan was implemented. A second rift was opened at the same place as the first. The mountain around it, a product of Chaos, resulted in an area of instability.
Ingu'lumin's knowledge of the Web of Magic was nowhere near that of Sarseg, so he paid the price by seeing his newly formed rift collapse upon itself, all because it lacked enough arcane energy from the Web to keep it stable.
- excerpt from the tome Izrukîn Sa Thir - "Acolyte of the Web"
When Ingu'lumin's Second Rift collapsed, it sucked most of the mountain back to Chaos. This left in its wake the great depression Zurukthûr. The volcano Gunul-Birum, named by the Mîmêk, is at the base of this five mile deep hole. Gunul-Birum is a mile high. Its internal fires come from an entropic core that is still linked to Chaos. The volcano is largely inhabited by salamanders left behind when most of the volcano was sucked back into Chaos. Fire archons and elementals were also once here, but all of these have moved on to other areas.