Cahyali: A smaller world where adventurers also hail from, which features much larger landmasses than Jearn.
Infero: The land of the dead, the fallen, once-beautiful plane of Cielo. It is the passing place that souls go to before reaching their afterlife.
Kurago: A plane of existence attached to most other planes.
Alpha Site: The Centralia Guild of Wizzards extra dimensional portal farm.
The Elemental Planes: Where the sources of elemental magic flow and ebb from, various types of magical flux pass through the Planar Sea and collide into the planes of Jaern and Cahyali. In some places, these planes may overlap with ours and create natural portals, allowing elemental beings to enter Jaern/Cahyali.
Jicania: The plane of terisium, originally discovered by Jican Trion of the University of RaForge on Torandor. Because terisium exists both on the material planes and Jicania, it can possess various multi-planar energy states, giving it magical properties. Jicania itself exists as sort of a grounding plane, where magic drains into. However, this natural property doesn't explain the presence of charged Terisium on Jaern.
Trion'kar: The plane of wild magic, originally postulated by Jican Trion of the University of RaForge on Torandor. Due to Jicania's properties of being a magical grounding plane, Jican theorized that some sort of catastropic event must occur for Terisium to energize beyond its ground state and exibit multi-planar properties. He believed that there must be a plane of wild and chaotic magic, in a unbound and free state, which is attracted to Jicania like opposite poles of a magnet, and collisions between the two cause Terisium to be charged.
The Planar Sea: The extradimensional space that planes of existence, well, exist in. Theoretically inhabitable to life (that we know of), and there is no current way to travel directly to the Planar Sea.