The End of the World
The Rift is rumored to be where the sea literally falls off the planet; however, it is really a deep chasm that not only swallows the ocean, but is also host to myriad phenomenon: a deep eternal lava flow which is a result of the friction created on the 4th dimension (time) that steams the ocean into clouds and recycles it quickly into the ecosystem; it is the birthplace of many of the Gods of __; Planar doors to all pockets and planes can be found here; it is the literal source of arcane magic, as magic alters the 4th dimension, and the rift is the source of that 4th dimension; the creatures that live here are epically powerful—maybe even more powerful than the gods; a plethora of artifacts that were involved in the world’s creation can be found here.
Beyond the literal chasm is a wavey network of planar navigation, and only truly epic characters need apply for adventures here. Crags, mountains, spires, stalagmites rise from deep within the rift, full of caves inhabited by strange and legendary NPCs; the lava flow creates an eternal wall of steam that will deal 20d20 damage to any adventurer foolhardy enough to try to dive through it (Reflex or Fortitude for half, but the DC is an incredible 42). While there are no “towns,” there are locations worth mentioning…
...and some legends say that on the other side of the rift, another world awaits to be discovered.