Cathedral With Crypts

Publisher's blurb: What secrets may lie hidden behind the grand stone architecture of the medieval Cathedral where it sits upon the hill, gazing down on the surrounding city? What mysteries lie within its hallowed walls? Clues to ancient puzzles, laid down by the architects of the church, perhaps? Or does the bishop hoard the knowledge of some blasphemous tome, locking it away from prying eyes? Perhaps some Eldritch horror lurks within the sacred walls or threatens to break in and lay siege to the congregation. In a fantasy setting, the cathedral may house friends or foes. Clerics with some knowledge, power or artefact that the party needs or perhaps they are an evil sect that the party are sworn to bring down. In the apocalyptic wasteland, the cathedral stands as a rallying point to desperate survivors, or is it the home of an apocalypse cult?