Koganusan is a massive dwarven mine/fortress built into the side of a volcano in the Demon Wastes.
The player characters discovered Koganusan from two different directions simultaneously; the player characters that had gone on the Expedition found it by sailing a ship upriver, while Gibbons found by going downriver thanks to directions from a wandering dwarf.
Koganusan was abandoned at the time of the player characters' exploration, and they entered primarily to find maps that could guide them out of the Demon Wastes.
Koganusan's volcano is one of a sizable mountain range. Although the Demon Wastes is known for its high volcanic activity and low soil quality, Koganusan's local range pushes the extremes of both. The area immediately outside its entrance is blackedned and lifeless. All plants or soil have been replaced with ash, obsidian and igenous rock. Charred skeletons remain here and there, the largest mostly consisting of elephants and the smallest mostly consisting of goblins still clad in melted iron armour. A river winds in from the north, passing under the volcano and emerging on the south side. There are modest signs of humanoid development outside of the fortress, including a bridge across the river, a half-melted platinum-plated statue peering out of a cavern, a scarred construction resembling a huge lizard, and an open, yawning drawbridge.
The inside of the fortress is industriously carved. The fortress is huge and chaotically designed - many wings and rooms were obviously added at different dates, and little of the layout seems to have been planned before construction. Koganusan includes every sort of facility you would need for a self-sufficient community, including barracks, armouries, nobles' quarters, common quarters, dining rooms, kitchens, butcheries, craftshops of every sort, jails, tombs and, of course, mines. Significant langmarks include an artificial moat, the bridged river, a titanic hall, huge mines deep in the mountain and many, many traps. Most of the walls, floor and even ceilings are covered in detailed carvings depicting events in Koganusan's history.
Koganusan was a well-chosen mine, as almost every metal, stone and gem seems available within the rock. The player characters discovered natural sapphires, emeralds, rubies and diamonds in the jeweler's shop; many of the items in the fortress are made of platinum, gold, silver or steel; the carved walls seem to switch from granite to felsite to gabbro to dolomite to microline at random. There is even adamantine located deep within the mines. Even to the casual observer, this combination of wildly different resources in such a small space is extremely improbable.
Although the area had previously been mapped by a squad of Silver Flame crusaders, it wasn't until approximately 995 YK that the Iron Council became aware of the mountain's extreme deposits. Koganusan was established in secret by a small mining party led by Torret Doge, but was quickly expanded and supplied with more crew as the Council dumped money into the project. Within months, thousands of square feet had been cleared in the mountain.
The first major problem the mine faced was the local wildlife. Every animal was uncharacteristically aggressive, including herbivores. Specifically, elephants. Said elephants were unusually organized and possessed of enough intelligence to not only hunt the dwarves, but siege the fortress after killing several dwarves outside the fortress in a surprise attack. Those still inside were aware of the danger, but had to watch the elephants sadistically "play" with their dying friends like cats with mice. A taboo in dwarven society against allowing bodies to rot without funeral rites led several dwarves to sneak outside; they hoped to retrive the bodies without being noticed. They were not successful. By the time the current ruler SRM put the fortress in lockdown, the elephants had learned enough to stick around, until they were eventually killed by intermittent crossbow fire using improvised bolts.
SRM had disappeared in the chaos, and in response to the elephants' violence, Koganusan's adminstrators appointed Sankis as the new leader due to his military experience. Sankis took a hardline approach to fortress defence, but the fort's next major obstacle was the declining mental health of its citizens. Although the majority of the fort remained healthy and stable, a disproportionately large segment began to suffer from depression, insomnia and even delusions. These issues came to a head when Sankis completed a project (designated the "Fuck the World Device") designed to pour magma into the fort's exterior. When the fort was next attacked, Sankis activated the device, only to see it burn several dwarves that were trapped outside, and fatally scald several more near the fort's entrances when the lava made contact with the stream. Sankis was so shaken by the events that he retired from his position, and began obsessively carving violent imagery into the fort's walls, including a massive storyline of his failure in the fort's largest hall.
Koganusan's administrators, sensing the declining morale of the fort's population, then appointed Momuzfikod, a bard, to the head position. Momuzfikod took on the title of "Overseer" and headed an aggressive propaganda project designed to lift the fort's spirits. He also ordered a massive expansion to the fort's mines, in an attempt to increase the fort's monetary output. Although his policies may have been attempts to give the populace an illusion of success, Momuzfikod's inexperienced and haphazard leadership opened the fort open to massive attacks. The expanded mine worsened the populace's mental health when it produced bizarre and unpleasant sounds that afflicted anyone in earshot; then, it worsened the populace's physical health when it produced bizarre and unpleasant demons that afflicted anyone in clawing distance. The demonic mob tore through many of the fort's dwarves, killing eighty percent of the standing guard before they were wiped out. The fort was then attacked by a horde of barbaric goblins, which gained access to the fort when they spotted Momuzfikod watching from a secret passage. Momuzfikod was stripped of his position and barred from working in the dungeon, and forced to beg for food or starve.
Momuzfikod was replaced by Giginlimul Fliergold, a military official sent by the Iron Council to restore order to the crumbling fortress. Fliergold, a harsh disciplinarian, tried to make an example of Sankis by throwing him into the prison on a trumped-up crime. However, Sankis was now so popular among the populace that Koganusan went into open revolt, with the administrators put under house arrest and the fort severing ties with the Mror Holds. Afterwards, Sankis - now too unstable to lead the fortress - was replaced by Megor Grendel, a longtime resident of the fort. However, the fort was now in too much chaos to accomplish anything; food was left to rot in the slaughterhouse, the stores were freely looted and scattered, and mining had stopped completely. In what was either a desperate attempt to focus the workers or just narcissistic insanity, Grendel mandated the construction of a massive statue in the shape of a lizard outside the fortress walls, with Sankis leading in charge of the decorative carving. However, since the fortress's security forces had all but disintegrated, the populace was forced to rely on Sankis's Fuck the World device for protection, and when clearing out another goblin attack, the lizard monument was ruined by the magma.
Watching his newest masterpieces being ruined by his greatest gaffe drove Sankis into a state of berserk fury. After smashing much of the fortress's outer fortifications, exposing the insides to the lava's extreme heat, Sankis caught aflame and ran unheeding through the halls, killing everyone he could find. Many of the fortress's population similarly snapped and began to attack everyone around them, in a widespread orgy of psychotic violence, wiping out nearly the entire population in only a few days.
- SRM: An accomplished banker and unmarked member of House Kundarak, SRM had the economic savvy to exploit Koganusan's material resources, though he believed he was really assigned there due to the influence of a business rival who wanted him out of the way. As a wealthy but low-status citizen of the Mror Holds, SRM held the fort's working class and noble administrators in equal disdain; his notes (written in Elven for the sake of privacy) derided both as incompetent "hoopleheads" in between lambasts of the fort's chaotic architecture and colourful strings of profanity. He eventually escaped the fort via a secret passage, resolving to start a new life.
- Sankis: A military veteran of common birth, Sankis began his reign with cunning, discipline and ambition. However, his mental state slowly but steadily degraded during his time in the fort; although his emphasis on fort defense saved its inhabitants from further elephant aggression, it eventually led to the accidental burnings and scaldings of some of its people. Sankis retired to a career of tortured artistry for some time, but was briefly returned to power late in Koganusan's life as the working class rebelled against the Mror Holds. Sankis evenutally sparked the fort's violent implosion with a murderous rampage, ending as a blackened skeleton in his tomb.
- Momuzfikod: Momuzfikod was a popular bard in Koganusan before being chosen to lead its people. His celebrity status, however, did not help him as self-described "Overseer". His expansions to the mines led to a massive demon attack, and his poor understanding of fort defense gutted its population. He narrowly avoided execution and was sentenced to live as a beggar; his corpse was found in a trashy closet at the end of the common dorms.
- Giginlimul Fliergold: As Koganusan's working staff began to show dangerous levels of unrest, military commander Fliergold was assigned to whip things back into shape. Fliergold's draconian leadership policies attempted to frighten the populace into keeping their heads down, but only galvanized their feelings of anger. Fliergold's attempt to make an example of Sankis instead led to an open revolt.
- Megor Grendel: A clerk and longtime resident of the fort, Grendel had techincally "led" Koganusan during a few of its first months before being replaced by noble administrators. Grendel took over after the revolution when it became clear that Sankis was too out of touch with reality to lead, but his rulership was short and unproductive. An ambitious monument in Koganusan's valley - whether intended to focus the workers' scattered energies or just a testament to the ruler's hubris - eventually led to the final downfall of Koganusan.
- Ber Onoldumat, Bookkeeper: A scientifically-minded bureaucrat, Onoldumat attempted to study the inspiration for the items produced in the fort's "strange mood" episodes. He eventually settled on the hypothesis that some psychic intelligence was present within the mines, behind the wall of adamantine. Further investigation drove him insane.
- Eshtan Ostarolon, Security: Brief mentions of Ostarolon in various security reports paint a timeline of his employment. Although at the bottom of the ranks when he entered the fort, Ostarolon rose through the ranks to become a talented fighter and one of the very few to survive its final self-destruction. Gibbons met Ostarolon upriver of Koganusan, who cautiously told Gibbons where to find the fort but swore he would never return there.
- Dodok Astlumash, Child: The daughter of two miners, Dodok survived Koganusan's final orgy of violence, probably due to her defensive nature, and spent weeks in a half-feral state of scavenging food and running from goblins. The party first encountered Dodok in a storage room full of bones, where she tried to escape by use of dumbwaiter but was captured by Gibbons and Weld. After being bribed with food (and the promise of more food), she served as a guide for the party and escaped with them to Blood Crescent.