IMPERIAL CITY, HUE, Vietnam: is a walled fortress & palace in the former capital of Vietnam. Building began in 1804 for Nguyễn Phúc Ánh, a warlord who took control of Vietnam & proclaimed himself Emperor Gia Long. Building began after his rule was recognized by China. The grounds of the Imperial City are protected by fortified ramparts ringed by a moat. The water in the moat is routed from the Huong River (Perfume River) through a series of sluice gates.