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The Facinora Basin was created in the same catastrophe that destroyed Eox's ecosystem, one far bigger than Golarion's Earthfall. Millions of cubic metres of rock were torn from the planet's surface and vaporised or launched into space, leaving behind a vast wound oozing with igneous rocks from Eox's core that surged up. Since then, gravity and erosion have barely erased this evidence of Eox's death throes.
The Facinora Basin is surrounded by a mountain range called the Fringe, which is twice as tall on the crater side and precipitously drops down to the floor. The ground of the crater is filled with obsidian, ashen boulders, and the sludgy remnants of old seas, as well as damaged magnetic fields and ley lines, ball lightning, strange flames, and magical transmutation storms. Geysers and volcanoes constantly erupt, destroying life and providing life-giving chemicals at the same time.
Hungry ghosts, killed by the cataclysm and cut off from the River of Souls by the violence of their deaths, roam the Facinora Basin in gibbering packs. This is the place where communication with them is easiest, but even the bone sages usually avoid doing that. Wildlife in the Facinora Basin includes glass serpents and strange creatures bred by the radiation like semi-intelligent grubs and ellicoths.
Despite its sheer danger, the Facinora Basin still sees visitors. Some of them seek the bizarre life forms adapted to Eox's environment, others study the fallout of the calamity or search for ancient relics, and still others want nothing more than power, but all tread carefully.