The Feywild

A magical, almost satirical take on its counterpart, the Feywild is an inversion of the Material plane. Its version of the continent is flipped upside-down, with the sea being the plane of reflection: every landmass in the Feywild is underwater in the Material Plane, and vice versa. The deep sea of Agrophon is a towering mountain on this plane.
The Feywild has no kingdoms or owned territory. If someone tries to claim land as their own, the resistance against them will never stop escalating until they die or disband. Surviving the Feywild is always possible and improbable. No form of permanence can be trusted, and creatures often succumb to random deaths, no matter how safe their population may be. They become part of the natural order, enduring a short lifespan and few comforts.
Most travelers from the Material Plane only visit out of necessity, and leave as soon as possible. Small groups have survived by avoiding attention, moving quickly and silently, and finding allies who can support them when things go wrong. Large groups don't fare well in the Feywild, unless they're extremely experienced or travel with people who are.

Geography

Elevation is easy to predict: the deeper a body of water in the Material Plane, the higher its landmass in the Feywild. Like the Shadowfell, this parallel is upheld by natural magic. When the dirt and sediment of the Feywild is moved or upset, it reasserts itself.

Fauna & Flora

Everything in the Feywild grows rapidly. The trees conduct a vicious arms race, stretching miles into the air to steal as much light as they can. Mushrooms can multiply at a visible rate and repopulate after any disaster. Many natural features possess some form of intelligence, cleverness, and sometimes sentience.

Type

Dimensional plane