(Source: Princes of the Apocalypse)

The dungeon under the Dessarin Hills that is the heart of the Princes of the Apocalypse campaign. This temple will be restyled for its customized history: The dungeon was originally a dwarven mine that taps into four elemental nodes in the deepest parts of the dungeons, designed to instill elemental energies into their craft. However, for everyone who creates or discovers a new form of energy for the betterment of society, there's another who would want to use it as a weapon. That's what the Elemental Cults come in. They wish to tap into these nodes of elemental energy to summon their four Elemental Princes to bring the material plane (Toril as a whole) to a primitive, "Natural" state. Read: Civilization is a virus on the planet, destroying the planet, and in order to save the planet they must destroy civilization. This will be the basis for the revised Princes of the Apocalypse.

You don’t even have to do the whole module. There is a chance that some campaigns nearby would want to go in there to fetch something, maybe to chase down some mid-carder feeb of pick up an artifact and weapon that’s stored there. It’s an excellent pre-made dungeon to work with on itself, and then there’s the Elemental Cults to work into.

(The Elemental Cults will only come into play during Princes of the Apocalypse.)

The Floors are in the same configuration and lettering in Princes of the Apocalypse, but the names of the floors are changed: