Since Duke Serjiad Corwen is the coordinator of the League, one might consider Maihama as the League's capital city. Like most other major cities, it is well-defended and is home to a rather large population.
From the anime map, it can be deduced that Maihama is situated somewhere in the middle of Japan.
Many of the People of the Land situated in Maihama became agitated by what they called the "May Revolution", after which the Adventurers gained intelligence and stopped taking quests from them for a duration of time. Shortly after Akihabara's formation of the Round Table Alliance, the League sent an invitation to the Alliance to attend a ball and meeting at the Ancient Palace of Eternal Ice.
During the meeting, an unprecedented occurrence arose: thousands of Sahuagin, Goblins, and other monsters began pouring into Eastal territory as a result of the Return of the Goblin King event. Feynail returns to Maihama to set up a defense against monsters that would attack the city and leaves Raynesia and Duke Sergead to tend to the Palace.
- In Expeditionary Force, fireworks can be seen coming from Cinderella Castle. In real life, Maihama is the location of Tokyo Disneyland.