Derring

Founded 500 years ago and kept hidden for many of those years Derring is the center for arcane arts. Located on the southern tip of the eastern continent and surrounded by three towns North Town to the north, East Town to the west, and West Town to the east. The four cities work in harmony trading in between themselves but are all separately ruled. Derring is the largest of the four cities and the most unique. Populated by mostly humans with small sprinklings of dryads, and Owl People almost all of them are wizards or are training to become wizards.

to just get my ideas out I'm putting down bullet points that I will make prettier later.
 * Ruled by a council of 7 secretive mages they communicate to their people though an elected face called the Profeteer
 * The city exports magical items and spell book copies to many cities through its docks.
 * They primarily trade with Avalon
 * The four cities get their food from East Town which is largely agricultural. West Town is located on a small iron mine. North Town is primarily slums of people who can not afford to live in the other cities.
 * West Towns mine does not produce enough high quality metal to make swords and armor so instead they make small things. Such as bindings for books, screws, locks, and secretly thieves tools.
 * People coming to visit Derring have started disappearing soon after entering the city. All of the missing persons have been young and powerful wizards. According to rumors around the docks if a lady clad lime robes appears to you in your dreams you are next to vanish.