Founded after the defeat of the Earth Kingdom, Crystal City is nestled underground in the heart of the northern mountains, west of Huo Jian Yu. The city is hidden from the spies of the Fire Nation and Phoenix Empire by extensive underground labyrinths and elaborate traps and tricks intended to let the trusted in and make the cities enemies disappear forever. Home to many thousands of people, refugees from the evils of the Empire, the city is a safe haven unknown to the Fire Nation or the Empire...

Now the bones of its former self, what was the Northern Water Tribe is a broken ruin of ice hiding a powerful secret -- the gateway to the Reach. The true North City is a fortress of ice which stands in the very heart of the North Pole, a powerful castle built of diamond-hard ice and guarded by a legion of warriors who rally to the Northern Queen's banner from all across the world. With an entrance only accessible by a waterbender hidden beneath the old Northern Water Tribe palace and a rail tunnel which would take days to travel without such bending to drive the icy carts, the Reach is well outside of the Empire's reach.