The Citadel, also has a nearly square form, with more than 600m long for each side, built of brick 4m high, 1m thick, around which is ditched a system of protection trench. Access to the Imperial City can be made by four entrance gates. Ngo Mon Gate is only used for the King.
Royal Citadel consists of more 100 beautiful constructional works divided many sectors:
- Tu Cam Thanh (Forbidden Citadel)
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, Tu Cam Thanh includes 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)…
- Pavilion of Edicts (Phu Van Lau)
Pavilion of Edicts is situated right in front of the Flag -Tower and by the National Highway No.1A which crosses Hue City. It is a delicate pavilion with a south view. In front of the Pavilion is a large court leading to the Nghinh Luong Pavilion (Pavilion for Fresh Air) on the Perfume River bank.
It is the building where Emperor’s edicts and lists of successful candidates of Thi Hoi (National Examination) and Thi Dinh (Court Examinations) were publicized. Though built early in Emperor Gia Long’s reign (1819), it was first decided by Emperor Minh Mang to be the site to publicly display his important edicts.
The pavilion was destroyed by a typhoon in 1904 and restored later by Emperor Thanh Thai.
- The Flag Tower
The Flag Tower, also called the King’s Knight, is the focal point of Hue City. It is commonly known as a flagpole, but viewed from the Imperial City; it is really a huge structure of three flat-top pyramids, one lying on top of another.
In feudal times, a yellow flag flapped everyday on top of the staff. It was replaced with a larger one on festive occasions (The Nam Giao Offering Ceremony, for example). Made of wool or velvet, this 4m by 3.6m flag was brocaded with a dragon design in its center and fringed with serrated lace.
- The Nine Dynastic Urns
Nine Dynastic Urns are located in the shade of the Hien Lam Pavilion, in front of the The Mieu Temple.
The nine Dynastic Urns are the greatest bronze ones in Vietnam They were cast by Emperor Minh Mang in 1836 to symbolize the sovereignty of the dynasty.
Each of them is named after the posthumous title of the emperors worshipped in the The Mieu Temple. For example, Cao Urn is named after Emperor The To Cao (Gia Long), Nhan Urn after Emperor Thanh To Nhan (Minh Mang), Chuong, Anh, Nghi, Tuyen and Thuan Urns after Emperors Thieu Tri, Tu Duc, Kien Phuoc, Dong Khanh and Khai Dinh respectively.
(Until 1958 only seven altars were established in The Mieu Temple corresponding to seven urns. Du and Huyen Urns did not exist yet).
- Principal Gate (Ngo Mon)
Principal Gate is located in front of the Throne Palace and facing the Flag Tower.
Ngo Mon is the main entrance to the Imperial City. Ngo Mon is a huge construction, U-shaped and consisting of two parts: below is a foundation made of brick, Thanh and Quang stone, above is a pavilion made of wood and roofed with tiles.
Throne Palace (Dien Thai Hoa) and Great Rites Court
Throne Palace (Dien Thai Hoa) faces the Ngo Mon Gate and lies right on the central axis of the Hue Citadel. The Throne Palace, or Palace of the Supreme Harmony, was the building for great court’s meetings. It was constructed in 1805 by Emperor Gia Long and used later in 1806 for his coronation.
- Dynastic Temple (The Mieu)
Dynastic Temple (The Mieu) is situated southwest of the Hue Citadel and facing south. It’s dedicated to ten Emperors of the Nguyen Dynasty, built by Emperor Minh Mang in 1821, it presents a 9 – compartment main building and a 11 – compartment front building, together connected in the “double” architecture with two bays on east and west sides.
- The Nine Holy Cannons
- Hien Lam Pavilion
Hien Lam Pavilion (Pavilion of the Glorious Coming) is situated in the center of the Dynastic Temple’s courtyard, southwest of the Hue Citadel. Built in 1824 by Emperor Minh Mang, at the same time as the Dynastic Temple, Hien Lam Pavilion consists of three stories.
- Nam Giao Esplanade
Nam Giao Esplanade is located about 4km south of Hue City. Nam Giao Esplanade is an open-air monument. It was built based on the dogma of heaven fate of Confucianism and has architecture of both the religious and political significance of Oriental feudalism.
- Royal Library (Thai Binh Lau)
Royal Library is located in the Forbidden Citadel. The Royal Library was the only monument undamaged in the Forbidden Citadel after the reoccupation of Hue by French troops in early 1947. It is the pavilion where the Emperors Nguyen came for reading and resting.
Royal Theater (Duyet Thi Duong)
Royal Theater is located in the east of the Quang Minh Palace (Palace of Brightness) in the Forbidden Citadel. The Royal Theater was the oldest of Vietnamese traditional stage that remained. It was closed after the end of the monarchy (Jan 8th, 1945).