The world of…(this and any other proper nouns will change many times, I’m sure) Auri (ore-rye) has a long history that dates back into ancient, forgotten history. Auri is no longer truly a world, but rather a series of magically linked lands referred to as “islands”.
Each floats in space. Picture a large chunk of rock, like an iceberg, floating in space. How much “earth” is below the ground level? Who knows. Some have caverns and passages dug into them, even mines. Has anyone ever come out the bottom? Not that anyone commonly knows. These islands float in space, occasionally visible by others, either in the distance, or almost close enough to leap to (how to get between them will be filled in, keep reading!). Sometimes they seem at the same ‘height’, sometimes lower or higher. They are in an atmosphere, they have blue skies, rains, starry nights, all the usual.
Islands vary in size, some less than an acre, some are as large as Greenland, or perhaps larger. All climate regions exist: desert, tundra, mountains, forest, ocean, plains.
At the boundary of each is some magical force. Things don’t fall off. Water doesn’t pour off (perhaps it jumps to the next island magically that would have been connected had the planet been whole?) You can’t roll on the grass and accidentally fall into space.
Culture is somewhat isolated due to this unique geography. Many cultures and races hear nothing but stories of other groups, and many people never leave their island or perhaps only travel to one or two others for business or pleasure. Other cultures live at major trade junctions and see numerous creatures and peoples come and go. Larger continent like islands are the main part of the world, and transportation is fairly typical (horses, wagons, boats, etc.) Others must transport everything via the portals and thus things are transported in smaller modes. Which leads us to: the portals.
There is at least one portal on each island (if there isn’t one on an island, no one knows about the island because it can’t be reached!). These are ancient ruins shaped like doorways. Sometimes they are in the middle of a town and are on a raised dais, clean and even decorated. Others are chipped and covered in vines in the middle of a jungle. Certain magics accessible to only a segment of the population activate the portals. The portals are large enough for a very small wagon to enter.
Beyond the portals is another plane, the MoonPlane. There it is eternally midnight with a full moon. The place is desolate and ruined. There is a path through the ruins from the portal to one or more portals, and only a portal opener can act as guide to traverse these paths. Little or nothing is thought to live in the MoonPlane.