Agathion (layer)

Agathion was the fourth and last layer of Pandemonium. The strangest and deadliest of all four layers, it consisted of isolated chambers within an infinite expanse of solid rock.

Geography
The broad tunnels of Pandesmos narrowed down progressively in Cocytus and Phlegethon until they reduced to nothing in Agathion. The layer was marked by dead ends and completely isolated caverns, accessible only by portals from the other layers and from other planes.

Only approximately half of the caverns of Agathion contained air. The other half of the chambers were in vacuum. In both cases, portals opening from other layers of Pandemonium invariably caused sudden and violent windstorms.

Rumors & Legends
The immense difficulty of locating the caverns of Agathion made them the perfect place for deities to hide a variety of items. Rumors existed of artifacts, mementos, powerful monsters, languages, and even cosmologies hidden away within the natural vaults. For additional security, some of these chambers were also populated with monsters charged with protecting the hidden item.