Elysium

The Blessed Fields of Elysium was the Great Wheel cosmology plane embodying the concept of pure good without being overly restricted by law nor dissipated by the randomness of chaos. Some characteristics of this plane were ascribed to Heliopolis and the House of Nature in the World Tree cosmology model when that cosmology became popular. Heliopolis was essentially destroyed in the Spellplague and the House of Nature split in at least two parts, one of which became the Deep Wilds and the other merged with the Green Fields as described by the World Axis cosmology model.

Description
Most features of the four layers of Elysium were found on or near the banks of the river Oceanus which linked the plane with two other Upper planes: the Beastlands and Arborea. Oceanus was the counterpart to the river Styx which flowed through the Lower planes except that Oceanus had only natural hazards and contained potable water. Lands near the riverbanks were lush with pines and flowering trees that filled the air with natural perfume. Farther from the river smaller trees grew and started to thin until finally, after hundreds of miles/kilometers, the forest gave way to fertile veldt regions, vast grasslands, and eventually badlands and desert.

There were no suns, moons, or stars in Elysium except those that the inhabiting Powers manifested, created by moving about in various vessels, or moving their entire realms across the skies. Depending on who or what was aloft, the shade of the sky could be deep indigo to a bright cerulean at any given moment.

Amoria
The first layer, Amoria, also referred to as the "innermost" layer, was connected to the Astral Plane by color pools and to Twin Paradises, Happy Hunting Grounds, and Concordant Opposition by unmarked portals located in dark caverns. Divination spells were required to determine the destination of these portals with certainty. Navigating the river Oceanus downstream also led to the Happy Hunting Grounds but any underground passages were not likely to be safe for boats. Amoria best fit the description given above and the river Oceanus had many side channels that split and merged back again, creating many "banks" for the establishment of realms.

Eronia
The second layer of Elysium was very mountainous and many branches of the Oceanus became spectacular waterfalls and tumbling cascades before forming channels bordered by steep cliffs of gray rock. Like Amoria, Eronia supported abundant wildlife along the banks.

Belierin
Contrary to Eronia, Belierin was mostly flat with marshes and wetlands stretching inland for miles/kilometers before larger plants and trees were found. Oceanus split and formed many island nations inhabited by extraplanar beings.

Thalasia
The fourth and "outermost" layer of Elysium was a great ocean, sometimes called the Thalasian sea, that was both the source and final destination of the River Oceanus. Small, green islands were scattered about, collectively known as Avalon. No big land masses existed here.

Inhabitants
In addition to the myriad species of fish and wildlife, the sentient beings that chose to live in Elysium were many of those species found in other Upper planes: hollyphants, planetars, solars, foo creatures, agathia, and baku. Moon dogs were numerous and widely used as servants and watchbeasts for the Greater and Lesser Powers of Elysium. The rare and magical phoenixes were native to this plane and spent most of their time here in the beautiful landscapes that Elysium offered, avoiding those that would hunt them for profit.

Afterlife
The spirits of those who perished in the service of good and those heroes the gods chose to spare from death were rewarded by being placed on the Isles of the Blessed in Thalasia. There, the living and the dead existed without responsibilities, had all their needs provided for, and could not be summoned or controlled.

Realms

 * Chauntea the Great Mother and Goddess of Agriculture once lived in Elysium.
 * Peaceful Eldath maintained her realm, the True Grove, on Eronia.
 * Enlil, the head of the Untheric pantheon, once made his home in the mountains of Eronia.
 * Hathor, Mulhorand's Nurturing Mother, had a realm named Succor in Amoria.
 * Hiatea, giant nature goddess, resided in Woodhaven in Eronia.
 * Ishtar, the goddess of love and war in the Untheric pantheon, once had a realm in Amoria centered on a great city surrounding a half-mile (800 meter) statue of herself. The statue glowed, supplying her realm with light.
 * Isis had a large realm in Amoria which she kept lit by lanterns in the trees and secured by patrolling moon dogs.
 * Lathander the Morninglord, God of Beginnings, Birth, Conception, Dawn, Eternal Youth, Renewal, Self-Perfection, Spring, and Vitality, had a rosy realm in Elysium.
 * Mystra (Midnight), the mortal that ascended to godhood during the Time of Troubles, eventually made her divine realm a shining city called Dweomerheart and placed it atop a large plateau in Eronia. Dweomerheart became its own plane in the World Tree cosmology model and was later destroyed upon the death of Mystra, in the resulting Spellplague.
 * Nanna-Sin, the Untheric god of the moon traveled throughout Elysium in his great barque shaped like a crescent moon bringing moonlight to all the banks of Oceanus.
 * Surminare, goddess of selkies, made her home named Selkies' Grotto on Thalasia.
 * Trishina maintained no permanent realm, but often wandered the sea of Thalasia and held and area for her petitioners there.
 * Urogalan, the Black Hound, halfling god of death, had his realm of Soulearth in Eronia.