Tu Cam Thanh
Located inside the Imperial City, behind the Throne Palace, the Forbidden Purple Citadel is reserved for Emperor and his family. Constructed early under reign of Emperor Gia Long in 1804 with brick walls of 3.72m high, 0.72m thick, about 1,230m in circumference. Its front and back sides are 324m each while either left and right side is more than 290m including 50 architectural constructions of different sizes and 7 gates for facilities of entrance and exit. Dai Cung Mon (the Great Palace Gate) is in the front side for the Kings. Can Chanh Palace (the place for daily working of Emperors). Can Thanh (Emperor's Private Palace), Khon Thai Residence (Queen's Private Apartment) reserved for the Queen. Duyet Thi Duong house (Royal Theatre), Thuong Thien (the kitchen for the Kings' food), Thai Binh Lau (King's reading room)...
Source: Vietnam Administration of Tourism