Feywild

Mirroring the Mortal Plane, no-one knows how it came to be. Together with the Shadowfell, it is one of two planes connected to the Mortal Plane through environmental portals. Environmental portals come into existence almost by random, but they all have something in common: they are spots where the Shadowfell/Feywild is almost exactly the same as the Mortal Plane. Most travellers don't notice this however, and soon they turn up in a world they've never seen before...

Known locations
While mostly uncharted, legends tell of huge amounts of villages all around the Feywild, and even some cities! One city known to sages across the Mortal Plane is Windwave, known for it's magical lake.