Yu Dao

Yu Dao was a town and Fire Nation colony in the western Earth Kingdom. It was the scene of great tension during the decolonization efforts that followed the war due to the difficulty of handling the removal of the Fire Nation civilians, many of whom had lived in the town for generations. The mayor of the town at the end of the war was Morishita.

The town's name, meaning "Jade Island", is likely derived from the greenery in the area. It also serves as a reminder of the town's Earth Kingdom origins, due to jade's green color.

History
Yu Dao was the oldest of the Fire Nation colonies in the Earth Kingdom, settled even before the Hundred Year War and settled with families as part of the Fire Nation's initial campaign of expansion. Despite its name, the city is not an island; it is located at the bottom of a valley surrounded by karst structures.

Prior to Fire Nation colonization, Yu Dao was a poor, backwater of a village. When the Fire Nation settlers came to the area, however, that all changed. Together with the Earth Kingdom civilians already living in the area, the Fire Nation created a thriving metalworking industry, boasted as the finest in the world. The tiny village grew into a thriving, cosmopolitan city. Through the unique blending of Earth Kingdom and Fire Nation culture, Yu Dao became one of the wealthiest cities in the world.

In 100 ASC, at the end of the Hundred Year War, Earth King Kuei and Fire Lord Zuko signed a treaty promoting the Harmony Restoration Movement, aimed at the removal of all Fire Nation colonies from Earth Kingdom territory. However, Yu Dao posed a particular problem due to its age, as many families had lived in the city for over one hundred years and had put down deep roots in the area. This led to conflict between Avatar Aang, Fire Lord Zuko, and Earth King Kuei.

Culture
The city's unique blend of Fire Nation and Earth Kingdom architecture gives the city a distinct feel. The architecture of the city represents a merging of both nation's architectural styles, Though the Earth Kingdom citizens generally occupied a second-class position in the city's society (though this was not universally the case; the Fire Nation mayor, Morishita's wife was an Earthbender, as was his daughter), Fire Lord Zuko observed that even so, the people were better off than they had been before the colony's foundation.

Trivia

 * Yu Dao was heavily based on Qingdao, a city in China that was a German colony from 1898 to 1918.