Dismal Caverns

Dismal Caverns was an Astral dominion in the World Axis cosmology model. Prior to the Spellplague it was known as Deep Caverns in the World Tree cosmology model. It was the home plane of the Great Mother, Ilsensine, Laogzed, and Ghaunadaur.

Description
This plane was a great solid mass of rock perforated by caverns, chasms, and tunnels of all sizes. There was no sky and no light except for that given off by luminous fungi and molten lava flows. Portions of the Caverns were subject to swift winds that howled through the maze of tunnels. Mapping the labyrinth of tunnels was completely impossible because within the demesnes of the deities the passageways and walls obeyed their will and could open, close, change direction, or collapse on an infernal whim.

Inhabitants
Dismal Caverns was the afterlife destination of most beholder, illithid, and troglodyte petitioners, and they appeared here much the same as they had in life. Their behavior was also similar as in their former lives and the disparate groups viewed each other with disdain, hatred, or animosity. Oozes, slimes, and abominations of all kinds also gathered here under the lurking eye of Ghaunadaur. The constant howling and particularly desolate and mournful tone of the winds that blew through regions of the Dismal Caverns attracted many howlers from their native Supreme Throne.

Realms
The realms of the most powerful inhabitants were widely separated because of the dislike and distrust between their rulers and it was difficult to determine where one domain ended and another began.
 * Ghaunadaur, the Elder Eye, once a member of the Drow Pantheon, retreated to this plane from the Demonweb Pits in the Year of the Lost Keep, 1379 DR. He was fed up with the machinations of the drow goddess Lolth and slunk away in order to rebuild his worshiper base.
 * The Great Mother of the beholders had a large demesne known as the Realm of a Million Eyes on this plane. She lived in a vast cave at the bottom of a region permeated by vertical shafts, which suited her floating petitioners and offspring. Her spawning ground was inviolable because she ate anyone who approached too closely, including her own children.
 * Ilsensine, the god of the mind flayers, ruled over the Caverns of Thought somewhere on this plane. This area echoed with its thoughts, so evil that every thinking creature eventually went mad.
 * Laogzed, the nearly mindless god of the troglodytes, scavenged the Rotting Plain&mdash;a huge cavern scattered with noisome lakes and ponds fed through myriad tunnels by the River of Blood which washed all the effluvium of the Fiendish planes through here, on its way to the Fated Depths. Laogzed's insatiable hunger caused him to eat everything he found, be it animal, vegetable, or mineral.