From PathfinderWiki
The Lost
Sphere Demiplane
Alignment None
Denizens Children of all races
Description Idealized realm of childhood innocence
For another meaning of "Lost", please see Petitioner#The lost.

The Lost is a demiplane which floats in the Ethereal and is home to children of countless races. The realm adapts itself to the childhood fantasies of its inhabitants and visitors, always appearing as places of nostalgic remembrance, especially if those places have ceased to be. These visions always impart a strong desire to remain and draw one deeper into this pocket realm. The children found there speak of a benevolent figure known as the Grandfather or Grandmother (depending on the child's experience), who is never glimpsed by those merely passing through. Unsettlingly, some children have spoken to visitors about "the time before they were children again" or "before they handed away their burden", but it remains a mystery as to whether this refers to an actual time or event, or if this kind of talk is merely a results of the demiplane's influence.[1]