General Fong's fortress is an Earth Kingdommilitary facility hidden within a mountain range on the west coast. It is one of the few remaining strongholds for the Earth Kingdom in the northwestern part of the country, resembling a small city. It includes barracks for the troops, guest quarters, a large infirmary to care for injured soldiers, a temple for prayer, and even a recreation area for soldiers to relax. The fortress holds extreme strategic significance to the Earth Kingdom, as its proximity to the Fire Nation mainland makes it well positioned for any potential invasion.
A few weeks after the Siege of the North, AvatarAang and his friends traveled to this fortress to seek transport to Omashu from GeneralFong, as Aang was expected to learn earthbending from KingBumi. After receiving a hero's welcome, Fong insisted that Aang was ready to fight the Fire Lord, as he was able to defeat the Fire Nation swiftly with the Avatar State at the North Pole. Aang knew he was not ready, but both he and Fong were intent on ending the Hundred Year War to stop the killing. After several failed attempts to activate the Avatar State and some good advice from Katara, Aang chose not to face the Fire Lord.
After announcing this to General Fong, the general and the entire fortress attacked Aang in an attempt to activate the Avatar State. After Fong tricked Aang into thinking he had killed Katara, Aang finally entered the Avatar State in rage, and thus created a shockwave that left the fortress badly damaged. Aang and his group then departed to Omashu alone to follow their own plans.