The city of Omashu is the second largest in the Earth Kingdom and the capital of one of its provinces. Ba Sing Se, the titanic walled capital of the Earth Kingdom is the only metropolitan area of greater size. The gates of this bustling metropolis are guarded by an army of earthbenders. This city is also well known for its famous delivery system powered by a combination of earthbending and gravity. The tall mountain peak on which Omashu was founded is located in the Kolau Mountains in the southwestern Earth Kingdom.
