The Imperial City (Vietnamese: Kinh th鄋h Hu?) in Hu? is a walled fortress and palace in the former capital of Vietnam. The grounds of the Imperial City were surrounded by a wall 2 kilometers by 2 kilometers; and the walls were surrounded by a moat.

The water from the moat was taken from the Song Huong (Perfume River) that flows through Hu?. This structure is called the citadel. Inside the citadel is the Imperial City; with a perimeter of almost 2.5 kilometers. Inside the Imperial City is the imperial enclosure called the Purple Forbidden City in Vietnamese; a term which follows that used by the Chinese for their own Forbidden City.

The enclosure was reserved for the Nguyen imperial family.