Free City of Greyhawk
The Free City of Greyhawk, sometimes called the Gem of the Flanaess, or the City of Thieves, is one of the largest cities known, and is certainly the most bustling with trade and adventure. The powerful Thieve’s Guild is rumored to run the city, which Lord-Mayor Nerof Gasgal doesn’t even bother to deny. The city is full of the greatest variety of people and things on Oerth, and as a result is one of the most cosmopolitan and tolerant anywhere. You might still get a knife in the back, but it’ll be for your gold, not your species or beliefs. The Free City is very free as the name implies, but “excessive magic” and the worship of most evil gods are banned, as well as other acts likely to cause chaos. Punishments are harsh.
The God Vecna and the Demigod Iuz both have a special hatred for Greyhawk, and have each sought to destroy it in the past.