At the heart of the Carcass Hills stands the ruin of an ancient city-state, known simply as The Citadel. The original name—if it had one—has been lost.
The Citadel was built on and into the largest hill, its walls and towers constructed from the same white limestone as the surrounding terrain. From a distance, the ruins blend into the hillside; only on approach do the worked stones become distinguishable from natural formations.
The city was substantial. Outer walls enclose perhaps two square miles; interior structures suggest a population of 20,000 or more at its height. The architecture is unfamiliar—geometric, angular, with an emphasis on vertical structures that seems designed for beings who could fly or didn't mind climbing. Windows are placed too high for convenient access. Doorways are narrow. Staircases spiral upward with steps uncomfortably tall for human legs.
The Citadel has been abandoned for at least 3,000 years, possibly much longer. The walls still stand in many sections, testament to the quality of the original construction, but roofs have collapsed and interior chambers have filled with debris. What remains above ground has been picked clean by centuries of cautious treasure seekers.
Below Ground
The surface structures are the least interesting part of The Citadel. The city extends downward into the limestone, with passages and chambers carved deep into the hill. The upper levels have been explored—barracks, storerooms, cisterns, the expected infrastructure of any fortified city. Below that, exploration becomes dangerous and maps become unreliable.
The deep levels contain architecture that doesn't match the surface city. The geometric precision gives way to organic curves; corridors narrow and branch unpredictably; chambers open onto vertical shafts of unknown depth. Some explorers report finding carvings that depicted scenes of worship or sacrifice. Others report nothing but empty stone.
What everyone reports is the feeling of being watched. The deep Citadel doesn't want visitors.
The Mass Graves
The correlation between The Citadel and the mass graves in the surrounding hills is obvious but unexplained. Were these the city's inhabitants, killed in some catastrophe? Enemies, slain in a great battle? Sacrifices, offered to whatever the city's rulers worshipped?
The bones offer few clues. They're too old for any remaining tissue, too jumbled for determining cause of death. They were buried deliberately—in some cases arranged in patterns—but the patterns' meaning is lost.
One popular theory holds that The Citadel was a center for some form of necromancy, and that the dead in the hills were raised to serve as laborers or soldiers. The steep, narrow architecture would make sense for a population of undead servitors who didn't need comfortable access. The mass graves would be the storage areas, waiting for reanimation.
This theory has no evidence beyond architectural speculation. But no better theory exists.