Home to The People of the Dream, it’s considered an off-limits world. It’s asleep, so to speak; nothing happens there. Nothing can be built. No resources can be mined.
It’s actually the first parallel world to be created, way back during the First War. Most of the People of the Dream went to it, voluntarily putting themselves under in order to escape the mess the First War was making of the world. There, they put themselves to sleep, in essence trying to wait it all out until the mess was over.
This had a far bigger consequence than anyone could have guessed at the time.
Some Dream stayed behind. They turned out to be the most important of all.