Pathfinder term for Feywild. Wiki article here.
The First World is so-called as it is believed to be the gods’ first draft of the plane that would later be split into the Universe and the Netherworld. The First World is a transitive plane that shares seams with the Universe.
The First World is unfinished and lacks the universal, fixed laws of physics. Various regions of this plane remain as testing grounds for different, unfinished, sometimes mutable and evolving physical properties. For example: gravity is inconsistent between parts of the First World, and the speed of light is arbitrary and variable. Where these inconsistent laws overlap can cause rather unpredictable reactions.
Explored Locations
The Thinlands in Session Whatever