The realm Haven is a dark dimension of memories that would later be known as the Underworld. It was secretly built by a group of Slayers led by Charon with the permission of the Archduke Azrael. They hoped that Haven could be a safe place from the Angelic Host where the souls of dead mortals could be kept and live comfortably while the war against Heaven continued. Building this new realm between Creation and the Second World, they hid it from others with a Veil of pain and suffering that made it impossible to be seen from the land of the living, but allowed those within to watch Creation.
During the War
At first, Haven was a largely desolate landscape with no permanent features. As the wraiths grew restless, Charon saw to it that things that were destroyed in the real world could be recreated from memory in Haven. This allowed the dead to bring treasured items with them, for tools and buildings to cross over, and eventually for entire cities to be forged. Later, the land of memories was altered to allow the dead to play out psychodramas and to split the soul in two parts so that they might converse, the better for the dead to recover and learn from the painful traumas they carried with them from the war in Creation.
As time went on, Charon continued to fear that the Host would find Haven and attack it as they had Kâsdejâ. He continued to build the realm out, creating a great sea of memories where small islands floated but could only be found by secret Byways. On one such island Charon built a great city where the oldest ghosts and his Fallen lieutenants would reside. Still unsatisfied, Charon built deeper, constructing a fortress beneath his city.