The Bastion itself seems to be located largely underground, as no windows or something similar is visible and the only part not built by the Twilight's Hammer appears to be the large lava sea Halfus Wyrmbreaker is watching over. If this is true, it may also be the reason how the Twilight's Hammer Cult could grow to powerful over the last years without any of the great forces of Azeroth noticing.
The ravings of some of the cult's more vocal members have been easy to dismiss as mere fancy in the past - but not once one has seen the Bastion of Twilight, the embodiment of the Hammer's fascination with new forms and transcending earthly bodies. The entrance to the bastion sits at the peak of theTwilight Citadel, atop a twisted elementium spire that points at the sky. Here, a portal waits to take the greatest Twilight aspirants... where? No one can say for certain.
What is clear is that the Leader of the Twilight's Hammer, Cho'gall, directs his forces from this dread place. And, whatever the location, it is certain to be near to the Old Gods who dwell beneath Azeroth, and give fruit to the darkest dreams of the living.
The Bastion of Twilight stands as a dark symbol of the Old Gods' burgeoning power on Azeroth. Various branches of the Twilight's Hammer dwell deep beneath the towering form -- considered the cult's foremost command center -- along with their twisted leader, Cho'gall. There, he and his servants conspire to bring the Old Gods' apocalyptic visions to fruition by bleeding Azeroth of all sanity, hope and life.