A Cloudsbreak World is surrounded on all sides by Impassible Boundary Mists. Boundary Mists are Boundaries. They are boundaries to rocks, pigeons, humans, small woodland animals and so on. None of these things can break this rule.
Most worlds are small.
However, There are a few larger worlds to the span of thousands of miles, but no planets. Cloudsbreak worlds do not have a physical means of communication with another cloudsbreak worlds excepting the dreamstate. Cloudsbreak worlds are NOT earth. Cloudsbreak worlds are not the Real world. This includes modern day, Ancient Egypt, The Wild West, etc.