Here is a brief overview. More follows in due course.
The name of the world is Regibry. If you really must have a reason for the name, translate it as Place of the Kings.
The Kings in question are all long-dead. Their tombs are in the catacombs below the Imperial Palaces in the two large cities which dominate this world.
Each of the cities is at the centre of a large empire. The empires are so large, and the cities so far apart, that war between them is impractical. Because of this, they have to find other ways of doing one another down.
Each city employs spies, to find out what the other city is up to. This is quite a good job for a player character.
Each city also employs guardsmen, to protect its Emperor from whatever it is that the other city is up to. This is not a particularly good job for a player character, as the reality is that neither city has anything to gain from assassination attempts. However, such employment would be a suitable sinecure for a retired or semi-retired player character.
Each city also has a commercial district in which wizards could earn a legitimate living and thieves could make themselves wealthy.
The natives of both cities are accustomed to visitors from other worlds, but do not themselves often travel to other worlds. They think their city is the most civilised in the Fifty Worlds, and it is only natural that people should want to live there.
The more interesting part of the world for player characters is the part outside the empires. There are at least two old-fashioned multi-level dungeons which are far from fully-explored and have plenty of monsters left in them. Until the discovery of the Maze on Yjsbso these were the places ambitious adventurers used to flock to.
The Pits are noted for the wide variety of interesting monsters living therein.
The region of Sabald is known for spiders. There is a multi-level dungeon there with a spider theme.
I may describe these in more detail in due course.