Apostae

Apostae is a small planetoid that orbits The Sun of the Golarion System, and has a highly inclined orbit, almost perpendicular to that of Absalom Station. It is generally believed that Apostae originated somewhere beyond the system and was caught in the sun's gravity thousands of years before The Gap, but whether this was a natural occurrence, or it was intentionally placed there is unknown.
Geography
Apostae is not an actual planet; it has no geological component, and its surface never changes without outside interference. The only major geographical features on Apostae are great cracks, craters with huge sidewalls and glassy bottoms, and towering slabs of rock torn from the surface. Hundreds of chasms cross Apostae, the largest of which are thousands of miles long and 40 miles deep. These chasms are never mentioned in pre-Gap records, and archaeology points to them being only 8 to 12 centuries old. The Azrinaran elves believe that they are the result of a forgotten weapon test during The Gap; other theories point to this being evidence that Apostae is literally coming apart. Other theories posit that Apostae is an ancient generation ship or another kind of self contained environment.
Apostae is a barren, airless world riddled with atmosphere-filled caverns and tunnels through to the planetoid's core. Many of these chambers are empty, but others hold ancient machines, permanently comatose alien forms, or vaults of advanced technology, magic, and weapons hidden behind impenetrable doors. The city's barren surface houses only one major settlement: the azrinaran elf-controlled city of Nightarch. Nightarch is the only known point of entry into Apostae's interior, with several other entrances on the world's surface blocked by huge, locked, and indestructible doors. Most of Apostae's interior has never been explored, and certain chambers mentioned in pre-Gap records like the Chamber of Life and Worldheart have never been found.
History
Pre-Gap
The few research teams who explored Apostae before The Gap encountered a now-extinct people called the ilee that dwelt inside the world's tunnels. Strangely, nothing in the records suggest the ilee themselves had any knowledge of their origin, giving rise to theories that they may have degenerated over millennia between the stars or may have been a captive, servitor race that outlived their masters. No one knows what happened to kill off the ilee.
During the Gap
During The Gap, many elves returned via the aiudara to their homeworld of Castrovel until the leaders of Sovyrian shut down the magical gates, leaving a small group of elves stranded on Golarion. Desperate to get off-world, the mages of the Azrinae family found a way to hot-wire the gates, opening a portal to a massive vault within Apostae's interior. The stranded elves fled through the aiudara but spend the next 68 years wandering through the subterranean tunnels and chambers, encountering numerous dangerous fleshwarps and abyssal chasms. They finally reached the surface through an ancient door they named Nightarch, after their first glimpse of Apostae's dark sky. Finally freed from their confinement, the azrinarans formed small communities under atmosphere-filled, magitech domes that eventually grew into a city. They also reached out to their neighboring planets, forming trade relationships with the inhabitants of Bretheda, Liavara, and Eox.
Post-Gap
Apostae has been attacked several times by the Elves of Castrovel since the end of The Gap in an effort to "cleanse the corruption" of their Azrinaran relatives. This resulted in the Pact Council imposing strict sanctions on the Castrovelians, but to little effect.
Recent History
Apostae was spared from the psychic shockwave that spread out from the destruction of the planet Aucturn in 324 by a shield named Zeizerer's Triumph. This ward had been worked on for centuries by the employees of Zeizerer Munitions. Any ship caught outside of the shield was destroyed or twisted into metal hunks crawling with undead.
Inhabitants
In addition to the ruling Azrinaran elves, Apostae is home to various other races that originated on Golarion including Orcs, dromaar, Kobolds, and Xulgaths. Despite centuries of effort to expand their holdings and increase their meager population, the elves only partially control the world's interior. Despite their lack of complete control of Apostae's interior and surface, the azrinaran elves still claim Apostae as their home world and became signatories of the Absalom Pact over the loud objection of the elves of Castrovel.
The majority of Apostae's surface is devoid of life, except for the rare few elementals. The interior of Apostae is home to numerous types of constructs, especially wandering berserkers and stoic guardians. Scout teams exploring the deeper parts of Apostae have also described seeing vicious, crab-like carnivores; communication with these teams is always lost shortly after this communication, and they are never seen again.
Government
Like the Bone Sages of Eox, Apostae's noble houses do not work together as a unified government and each controls an independent fiefdom in the planet's surface settlements. They only come together to elect ambassadors from among the elites of each house every two years according to the laws of the Absalom Pact. These ambassadorships are seen by the elves as a double-edged sword, skyrocketing some careers while dooming others. Beyond this, each house acts independently, most operating as family-run corporations that deal in arms or other technology retro-engineered from what has been discovered in the sub-surface tunnels, and chambers of Apostae. The most powerful house is House Zeizerer, which controls the surface city of Nightarch. Orcs, dromaar, and others who live in elf settlements are second-class citizens at best, with no say in political matters, and are treated mostly as laborers or subterranean cannon-fodder by the elves.
Settlements
Nightarch is the largest of the numerous cities built under magitech domes that are filled with breathable atmospheres on Apostae's otherwise airless surface. A major spaceport, the city hosts bustling markets selling personal and starship weaponry, mercenary squads of orc and half-orc warriors, fleshwarping augmentations, and custom weapon designs. Visitors often come through the city to search for alien technology in the caverns below, either on official contract or by slipping through the Azrinaran elves' defenses. Visitors also come to study the eponymous arch at the city's center. The arch is similar to many others in the city that link it with most of the other Pact Worlds but is covered in strange markings that defy all efforts at analysis. The arch activates spontaneously at rare and random intervals creating a gate to unknown landscapes; so far none who have entered the portal have ever returned.
Economy
Apostae's biggest export is munitions manufactured by Arabani Arms Ltd. and Zeizerer Munitions, the largest of the two corporations controlled by the Azrinaran elves. These two corporations have been feuding for centuries, but due to their importance, have considerable influence over Apostae's economy and governance. Smaller companies exist below them that are forced to use assassination, espionage, and other underhanded means to further their political and economic advancement.
Religion
The most common form of worship is of these is the church of Eloritu, the Ibra, and Zon-Shelyn.