Nightwick Abbey is the setting I developed for my previous Swords & Wizardry game. It's somewhat modeled on the premise of Old School apologist James Maliszewski's aborted effort to create a community megadungeon. I took the idea of an abbey built over a font of chaos and tweaked it.
Nightwick Abbey and its accompanying dungeons are labyrinthine and strange in the mythic underworld style. The Abbey itself was constructed over the grave of a long dead, and thoroughly evil, God. In digging the dungeons, the templar style warrior-monks encountered the lingering essence of this creature and were compelled to commit savage atrocities in its name. The order has since been eradicated, but not before leaving a scar on the land. Ruins of villages they destroyed, temples they both constructed and looted, and fortifications they built lie scattered across the land. None loom as large or as fearsome as their primary chapter house: Nightwick Abbey. Its halls are rumored to be infinite, and constantly shifting. In its deepest belly lies an undead god, waiting to be free.
Other things inhabit the World of Nightwick of course, but I thought I'd establish a sort of rough idea of what I'm talking about before I deal with those topics in detail. Many, if not most, of my future posts will detail elements of the setting.
Edit: fixed some grammatical errors and weird formatting issues.