The Tongguan Palace is the palace where the Sovereign of Gen resides. It's said that in the past, the Great General actually stationed his troops on the old site of the Tongguan Palace, training soldiers and guarding the Northern Fan. Later, as the military camp expanded, the Ye Capital City gradually took shape.
Later on, after the great victory in the Northern Expedition, the world was pacified, and the seas were cleared. Emperor Wu undertook massive construction projects, using the wealth heaped up like mountains in the arsenal and inner treasury to build the three platforms: Copper Stork, Golden Phoenix, and Jade Qilin.
