The Feywild
The mundane world is a hemisphere, as any child knows. The other half of the world is the Feywild—although, since the Feywild is unstable in all ways, it’s impossible to say whether it too forms a hemisphere, or any other shape. Relative to the mundane world, the Feywild is the otherworld—literally the world of Otherness—but it’s also a real, existing place; the PCs could walk there, if there didn’t happen to be a large ocean in the way. In addition to this, the mundane world is in some places pierced by holes like gateways, that lead directly into the Feywild—and then, sometimes, directly back out into the mundane world. These holes in the fabric of the material world are called fey doors. Sometimes travelling through a fey door takes you to the Feywild; more often, it leads to some other part of the mundane world, so that the traveller moves through the Feywild without ever actually being there.
According to the stories, the Feywild has a single ruler; she goes by various names in the mundane world, but the most common is the Queen of the Green Court. She is generally imagined as holding sway over an enormous tangled forest, but this is probably pure imagination. The stories say she never leaves the Feywild; perhaps she can't.
The Feywild's unstable nature
The mundane world has five fixed points, as opposed to the two poles of a sphere: North, South, East, West, and the furthest spot from the Feywild, which is generally called Noon. These are referred to as Points, not poles: Point of East, Point of Noon, etc. It’s a common convention to orient maps with Point of Noon at the top, and the Feywild at the bottom, but this is confusing to people raised on spheres.
By contrast, the Feywild has no fixed points; in fact nothing is fixed there at all, from geometry to geography. Mutability is the only constant in the Feywild. Because of this, mundane visitors to the Feywild usually can't remember anything about it once they return to the mundane world. (Game play: characters returning from the Feywild must make a DC13 Wisdom saving throw. On failure, they can't remember anything about their experiences in the Feywild; on success, they can remember only hazy, disconnected images and impressions.)
History: the cataclysm
The most common story goes that thousands of years ago—much longer than anyone can tell—the Feywild and the mundane world were intermingled. Then some kind of cataclysm separated the two, so that each occupies its own half of the world—supposedly in complete separation, though in fact pockets of Feywild pop up in the mundane world, like holes in cheese.
However, some people believe that the mundane world and the Feywild were once completely separate, and the cataclysm was a collision between the two that resulted in the current shape of the world. The only thing that everyone agrees upon is that something happened back then, but no one knows even how long ago, let alone the nature of the cataclysm. It must have been at least 5000 years ago, maybe much longer.
Non-elves sometimes assume elves must know more about this than others, being long-lived and of fey origin. In fact, elves' individual memories last much less time than their lifespans , and they frown on anything but oral history, whose truth is sometimes largely symbolic. They don't really know any more about deep history than anyone else.
The Feywaters
The Feywaters is the name given by the Maveren to the western part of the Aldean Ocean, close to the physical border of the Feywild. Things get a little strange the closer you get to the Feywild itself; more monsters, less stable geography. Amongst humans, it's sometimes rumoured that sailing too long in the Feywaters can drive you mad.
A couple of centuries ago, the Maveren fought a series of battles and raids with various fey peoples in the Feywaters; according to skaldic sagas, this eventually escalated into a contest with the Queen of the Green Court herself, or at least with her personal representatives. This segment of Maveren history is called the Feywaters War.
