Arborea

Larger than life, Arborea is a place of violent moods and deep affections, of whim backed by steel, and of passions that blaze brightly until they burn out. Its good-natured inhabitants are dedicated to fighting evil, but their reckless emotions sometimes break free with devastating consequences. Rage is as common and as honoured as joy in Arborea. There the mountains and forests are extravagantly massive and beautiful, and every glade and stream is inhabited by nature spirits that brook no infringement. Travelers must tread lightly. Arborea is home to many elves and elven deities. Elves born on this plane have the celestial type and are wild at heart, ready to battle evil in a heartbeat. Otherwise, they look and behave like normal elves.
Intense Yearning- Keep track of how many days a visitor spends on Arborea. When the visitor leaves, it must make a Charisma saving throw against a DC of 5, plus 1 for each day spent on the plane. On a failed save, the creature becomes afflicted with a yearning to return to Arborea. As long as the effect persists, the creature has disadvantage on ability checks. At the end of each long rest, the creature can repeat the saving throw, ending the effect on a success. A dispel evil and good spell removes this effect from the creature. (Source: DMG D&D)
Arvandor- The layer of Arvandor was sometimes referred to as Olympus. Its two realms—so vast and influential that their names became synonymous with the plane and the layer they occupied—coexisted with little conflict: Olympus, home to Lyra. Indeed, the two domains were separated by thousands of miles/kilometers of unclaimed wilderness and, due to the slight curvature of the landscape, were not visible to each other despite being located at the highest peaks of their respective lands. The layer also had a third realm known as Brightwater.
This layer was starkly mountainous with deep chasms, huge passes, and foothills the size of Prime plane mountains. Giant trees adorned the rugged terrain while the flatter parts were covered with untended vineyards, orchards and fields of wild wheat, eventually giving way to wilderness. Monsters and evil beasts took advantage of the lack of vigilance and roamed the wild places, providing a challenge to any who would go exploring.
Aquallor- Aquallor to the elves, this layer was mostly filled with shallow seas no more than three feet (one meter) deep, with no islands or shores. The River Oceanus had its outlet here, delivering travelers from Elysium or the Beastlands safely in the middle of nowhere. The mighty sea was wracked with powerful storms. The shallow seabed was occasionally broken by cavernous trenches leading to undersea domains of various sea gods or by huge maelstroms that funneled water back to Thalasia in Elysium, thus completing the cycle. The barriers between layers of this plane were somewhat rare compared to other Outer planes. Being the middle layer, Aquallor had barriers that led to the watery realms of Poseidon and Deep Sashelas in Arvandor, as well as a few that lead to the third layer, Mithardir. Aquallor was also home to many sea elves and other aquatic creatures.
Mithardir- Mithardir meant white dust in the Elven language, and the mysterious third layer was a land of blowing white sand, with snow in the colder regions. The elves had stories and legends about powerful beings who once lived here, creating artefacts and architecture that became all but buried in the dust after they presumably died or departed. Their fate, and that of any creatures left behind, remains unknown.
Inhabitants Devas, hollyphants, planetars, solars, foo creatures, and agathia formed the usual cohort of creatures ubiquitous to the Upper planes. But Arvandor was also the home of giant beasts and legendary monsters, such as giant bears, eagles, wolves, serpents, boars, lions, and wild cattle. Gorgons, cyclopes, giants, medusae, chimerae, harpies, sphinxes, and pegasi all made nests or lairs in the mountainous terrain or lived and lurked in the wilderness of the first layer. (https://forgottenrealms.fandom.com/wiki/Arborea)

Alternative Name(s)

The Olympian Glades

Location under

Outer Planes

Owner/Ruler

Lyra

Ruling/Owning Rank

Goddess