Belierin

Description 
Belierin, sometimes called the Forgotten Layer, was the third and least known layer of Elysium. An endless land of swamps and marshes covered by an eerily luminous mist, it was also rumored to be the prison of an ancient legendary Hydra and possibly other powerful entities. The River Oceanus flowed slowly through Belierin in a tangle of channels that braided around sandbars and mangrove forests. In some places, rocky ridges rose above the bog, making for stable terrain. A few communities and towns were located in those places, usually built around lighthouses that served as navigation beacons to aid travelers. Despite the generally desolate nature of the layer, the good influence of Elysium could still be felt in Belierin, in the form of the shiny nature of the fog itself and a luminous vapor that surrounded every light source.
In ancient times, the Guardinals encountered a legendary Hydra in one of their quests, thought to be the mythical unique individual that spawned all other Hydras. Unable to defeat it, the Guardinals used a teleport spell to move the Hydra to Belierin, after which they closed all portals that led out of the layer and sealed it off from divination magic. This effectively turned the layer into an infinite cage, from which the only exit was the Oceanus itself, whose blessed waters the Hydra could not touch.
It was rumored that other powerful entities shared the prison with the Hydra. The number and nature of the other prisoners was not known, but rumors existed of a creature similar to the Tarrasque, a Legendary Black Dragon, a Captured Archdevil, a Demon Lord, an Archo-Mental, or even a Wounded Deity.

Natives
Guardinals
Quesar 
Tuning Forks
Gold; E Minor
Notable Locations
Nillis-Thur (Hidden Angel Fortress)
Quesar's Birthplace
Rubicon (Last Guardinal Outpost)

Planar Traits

Shape and Size
Infinite size
Gravity
Normal
Time
Normal
Morphic Trait
Divinely
Magic Trait
Normal

Type

Dimensional plane