A world whose lands are made up of huge terrain spheres that rotate constantly with most portion underwater. As time passes, the shape of the bodies of water change, landmarks shift inside the new border lines, and mountains tilt to different degrees. Land dwellers are gypsies that can never build anything permanent, and somewhat ironically, the only stable settlements are large structures built at sea.
A society in which people believe that the hundreds of stars that dot the sky are the dreams of the sleeping. When the sun goes down, and the people of the world rest, the dreams begin to seed the sky, disappearing in the morning as the populace awakes once more. It could be just a folk tale, or it could be real...