Abeir

Abeir was the twin planet of Toril, located in is own material plane.

Geography
Abeir had steel-colored sky and a blue sun. The only known continents of Abeir were Shyr and Laerakond. Those lands were inhabited primarily by Primordials, dragons, dragonborn, dwarves, genasi, and humans, but also were home to most of the other races that inhabited Toril. Like Toril, it also contained an Underdark inhabited by drow.

For a time, Maztica was also part of this world.

Magic
Magic didn't exist naturally on Abeir, as there was no Weave and not a way to contact any gods, as gods were wary about this world. Planar magic, such as that granted to warlocks by a pact, was also ineffective, and creating portals to Abeir was nearly impossible. The only magic that worked on Abeir was that a creature could create on its own, such as the inherent elemental magic a primordial had in its body or a dragon's breath. Magic items also worked on Abeir, and abeiran dragons usually scavenged primordial corpses in order to create powerful artifacts from their remains, such as the Breath of Petron.

History
After Ao sundered the world of Abeir-Toril, splitting it into the two twin planets, Abeir and Toril, he gave Abeir to the few primordials that survived the Dawn War to rule. Those primordials were tired of war and were unable to overcome their dragon steeds when those rebelled against them. The primordials were quickly defeated and those who survived retreated into hiding and fell silent. Soon after the primordials disappeared, the War of Fang and Talon began and only few dragon lords survived.

After the war, a mighty dragon called Gorloun founded the first dragon empire, and soon rival draconic realms sprang up thereafter, and the long Rule of Dragons began. In the lands of the eastern continent Shyr, the despotic primordial Karshimis also created his own nation. These nations quarreled each other for ages, but draconic rule remained nearly unchallenged until the Blue Breath of Change, when both worlds merged for a certain time. Laerakond and other regions of Abeir were transported to Toril, and the fate of the remaining nations in the world of Abeir became a mystery to Faerûnian sages.