Source: The Worldwound, pg(s). 8f.
Jormurdun is one of the ten ancient Sky Citadels built by the newly-emergent dwarves at the end of their Quest for Sky. It is located in the Wolfcrags, a largely uninhabited range of hills in the northwest of the Sarkoris Scar's (formerly the Worldwound's) Frostmire region. Like other Sky Citadels, Jormurdun was built almost completely underground. Roughly two-thirds of its subterranean chambers are filled with still-functioning dwarven traps laid there by its departing inhabitants thousands of years ago, while the rest is the domain of a clan of duergar who have recently been converted from their ancestral worship of Droskar to that of the demon lord Shivaska by her chosen, the kalavakus demon Yealek-Vor.
The Pathfinder Society took a personal interest in Jormurdun, successfully locating and securing the entrance in 4714 AR. Expeditions later recovered King Gutheran's piece of the Sky Key that same year.
Around 1600 AR, duergar attacked the citadel and conquered it. The dwarves who survived the attack fled, while Gutheran, the last king of the Sky Citadel, broke the Sky Key into five pieces, keeping one piece for himself and handing a piece to each of his heirs, and hoped that one day the Key would reassemble and the dwarves would return to Jormurdun.
As has already been stated, almost all of Jormurdun is located underground. The only visible outbuilding on the surface is a single three-story tower that sits on the edge of a cliff several hundred feet in height. The tower and the mountainside it sits upon look innocuous, except when the light of the sun combines with the Worldwound's unusual weather and reveal ancient, eroded carvings of dwarven faces carved into the cliffside. Many hard to distinguish windows dot the eastern face of the mountain as well, either cleverly hidden in the rock's natural formations, or else sealed by stone shutters from the inside. These windows once led in the morning light, but have been closed for thousands of years.
Approximately two-thirds of the below-ground chambers and halls of Jormurdun are filled with ancient dwarven traps or guardians, or are now the lair of denizens of the Darklands who have traveled up to the Sky Citadel from below. The rest have fallen under the control of a band of grey dwarves who worship the demon lord Shivaska.
Besides the Darklands creatures who live home in Jormurdun, the halls of the Sky Citadel were inhabited by a clan of duergar led by a kalavakus demon named Yealek-Vor. Yealek-Vor was a devotee of the demon lord Shivaska and discovered Jormurdun in 4689 AR. Although they once were loyal followers of Droskar, Yealek-Vor converted most of the duergar to the worship of his demonic patron. The grey dwarves scoured the halls for ancient dwarven artifacts, hoping to use them to further their demonic patron's stature within the Worldwound, until they were defeated by the Pathfinder Society in 4715 AR.
- James Jacobs, Jonathan H. Keith, Jason Nelson, Todd Stewart, and Tanith Tyrr. (2013). The Worldwound, p. 8–9. Paizo Publishing, LLC. ISBN 978-1-60125-532-7
- Adam Daigle. (2014). Beyond the Campaign. City of Locusts, p. 66. Paizo Publishing, LLC. ISBN 978-1-60125-587-7
- Vanessa Hoskins. (2015). From Under Ice, p. 3. Paizo Inc.
- Pedro Coelho. (2015). Test of Tar Kuata, p. 3. Paizo Inc.
- James Jacobs, Jonathan H. Keith, Jason Nelson, Todd Stewart, and Tanith Tyrr. (2013). The Worldwound, p. rear inside cover. Paizo Publishing, LLC. ISBN 978-1-60125-532-7
- Crystal Frasier. (2015). The Sky Key Solution, p. 39. Paizo Inc.
- Kate Baker et al. (2020). Lost Omens Pathfinder Society Guide, p. 13. Paizo Inc. ISBN 978-1-64078-278-5
- This date is based on the publication date of The Sky Key Solution and the mention on p. 13 of the Lost Omens Pathfinder Society Guide that Yealek-Vor had been defeated.