Cosmology

The Material Plane that holds the world of Toril is one of many planes of existence. Beyond Toril lie the Elemental Planes, the Positive and Negative Energy planes, and many realms of the deities, demons and devils (collectively called the Outer Planes). The Ethereal and Shadow planes overlap the the Material, with the Astral Plane connecting to all of them. The Deity Gargauth dwells on the Material Plane.

The Elemental Planes
The Elemental Planes embody the four basic elements in nature, air, earth, fire and water. The planes are extremely inhospitable except for natives of the plane, such as elementals, genies, mephits and other outsiders. Each Elemental Lord also make their home in the elemental planes.

Akadi rules the Elemental Plane of Air. Grumbar rules the Elemental Plane of Earth. Kossuth rules the Elemental Plane of Fire. And Istishia rules the Elemental Plane of Water.

The Energy Planes
The Negative and Positive Energy Planes are no less extreme than their elemental counterparts, and very few beings are native to these planes. No dieties make their home in either plane.

The Ethereal Plane
The Ethreal Plane is a misty continuum that coexists with the Material Plane. Individuals within the Ethereal Plane can see into the Material Plane, but not vice versa. It is accessed by spells such as etherealness and ethereal jaunt, as well as various portals scattered through the Realms and the planescape.

The Shadow Plane
The Shadow Plane is coexistent with the Material Plane, but all colors are drained from the world, everything appearing in gray-tones, the other senses of hearing and touch are also dulled when in this eerie plane. The most common way of accessing the plane is through spells and abbilities like shadow walk, most often used for covering great distances on the Material Plane undetected and unhindered, although the strange Shadow Plane may provide hinderences of its own. Mask and Shar both make their homes within the Shadow Plane.

The Astral Plane
The Astral is an open empty plane, it has no directional gravity so travelers are weightless. The few bits of matter scattered throughout the wast plane are mostly portals leading to every plane in the cosmology. Spells like astral projection and gate access the Astral Plane in one form or another. The deity Ulutiu is suspended in a voluntary stasis within the plane, slumbering unaware that Auril is draining his divine powers ever so slowly.

The Abyss
Home of many demon lords, sages theorize the plane has 666 layers.

Arvandor
Home plane of the Elven Pantheon and the drow goddess Eilistraee. Hanali Celanil maintains a portal to Sune's realm in Brightwater, and the entire pantheon maintains a portal'' to the House of Nature. Everan Ilesere maintains a portal to the realm of Hlal in Dragon Eyrie.

The Barrens of Doom and Despair
Home plane of Bane (isolated location), Besheba, Hoar, Loviatar, and Talona.

Brightwater
Home plane of Lliira, Sharess, Sune, Tymora and Waukeen. Sune maintains a portal from her realm to Hanali Celanil's realm in Arvandor. Sharess also has a small realm on Heliopolis, the home of her native pantheon. Tymora maintains a portal to Green Fields.

Cynosure
Cynosure is a small plane located very close - cosomologically speaking - to Toril. It is a plane only accessable to deities, and they can only access it from within their own domains. The plane is considered neutral ground by all the powers of Faerûn, and the plane is used as a meeting ground to settle disputes and decide upon punishments for those deities who upset the Balance (as defined by the guidelines Ao left).

The only way in and out of Cynosure is through the portals leading to each deities realm, and it cannot be accessed by spells that normally allow planar travel, so the plane cannot be used as a way station as Toril can. There can at times be several deities meeting in Cynosure, and yet other times the demi-plane lies empty for extended periods of time.

While portals from Cynosure lead to the realms of the Elemental Lords, none of them have ever been known to appear on the meeting plane.

Demonweb Pits
Home of Lolth and the drow pantheon. (Eilistraee has a realm here, but she rarely visits it). The pantheon maintains several portals to the Abyss.

Dragon Eyrie
Home of the dragon pantheon. Tiamat maintains a portal to this plane. Hlal maintains a portal to the realm of Erevan Ilesere in Arvandor.

Dwarfhome
Home of Moradin and the rest of the dwarven pantheon, except for the duergar and derro deities.

Dweomerheart
Home plane of Azuth and Mystra, as well as their subordinates Savras and Velsharoon. Velsharoon is generally not trusted by the other deities, but they suffer his company, and he suffers theirs to gain protection from Talos.

The Fugue Plane
Home of Jergal and Kelemvor.

Fury's Heart
Home of the destructive deities Auril, Malar, Talos, and Umberlee.

Gates of the Moon
Home of Selûne, Finder Wyrvenspur, and Shaundakul.

The Golden Hills
Home of the gnome pantheon, excluding Urdlen (whose realm is adjacent to the Abyss). The Golden Hills also connects to the realm of Gond.

Green Fields
Home of the halfling pantheon. Brandobaris has a realm here, but he rarely resides in it, preferring to establish a small, temporary realm wherever he rests. Green Fields has a connection to the realm of Tymora.

Hammergrim
Home of the duergar deities Deep Duerra and Laduguer.

Heliopolis
Home of the Mulhorandi pantheon and Tiamat who maintains a portal to the Dragon Eyrie.

House of Knowledge
Home of Deneir, Gond, Milil, and Oghma. Gond maintains a portal to the Golden Hills.

House of Nature
Home of Chauntea, Eldath, Gwaeron Windstrom, Lathander, Lurue, Mielikki, Nobanion, Shiallia, Silvanus, Ubtao and various animal lords and the deities of many nature-oriented creatures (e.g. centaurs). The deities of the plane maintain a portal to Arvandor.

House of the Triad
Home of Helm, Ilmater, Siamorphe, Torm and Tyr.

The Nine Hells
Also known as Baator, the Nine Hells is home of the Nine (archdevils) and various other devils and evil outsiders. Some of them maintain portals to the realms of Bane, Loviatar, and Talona.

Nishrek
Home of the orc pantheon.

The Supreme Throne
Home of Cyric.

Warriror's Rest
Home of Garagos (hostile to the other deities residing in Warrior's Rest), Red Knight, Tempus, Uthgar (distant from all but Tempus) and Valkur.