Republic City is the capital city of the United Republic of Nations as well as one of the largest and most modern cities in the world, with a population of millions. Located on the shores of Yue Bay, it is built upon what was once the territory of a Fire Nation colony and was founded by Fire Lord Zuko and Avatar Aang after the conclusion of the Hundred Year War as a haven for immigrants from all across the four nations. Being a modern urban center, Republic City boasts significant high-rise development as well as the widespread use of automobiles, motorcycles, and airships.
Republic City is home to a variety of iconic landmarks. These include a monumental statue of Avatar Aang in Yue Bay, a spacious city park, many suspension bridges, and skyscrapers. The police force utilizes metalbending for civil law enforcement. Pro-bending is the city's most popular form of sporting.