The Imperial City (Vietnamese: Hoàng thành; chữ Hán: 皇城) is a walled enclosure within the citadel (Kinh thành; chữ Hán: 京城) of the city of Huế, the former imperial capital of Vietnam during the Nguyễn dynasty. It contains the palaces that housed the imperial family, as well as shrines, gardens, and villas for mandarins. Constructed in 1803 under Emperor Gia Long as a new capital, it mostly served a ceremonial function during the French colonial period. After the end of the monarchy in 1945, it suffered heavy damage and neglect during the Indochina Wars through the 1980s. The Imperial City was designated as a UNESCO World Heritage Site in 1993 as part of The Complex of Huế Monuments and is undergoing restoration.

In June 1802, after more than a century of division and the defeat of the Tây Sơn dynasty, Nguyễn Ánh ascended the throne of a unified Vietnam and proclaimed himself Emperor Gia Long. With a nation now stretching from the Red River Delta to the Mekong Delta, Emperor Gia Long moved the capital from the northern Thăng Long (current Hanoi) to Huế, the ancestral seat of the Nguyễn lords. Gia Long looked to "Confucianism and Chinese models of statecraft" as the best modes of authority, and with this ideology, he ordered the construction of a palace complex based on Beijing's Forbidden City in Huế. Geomancers were consulted as to a propitious location site for the new city, and construction began in 1803. Thousands of workers were ordered to build the walled citadel and ringing moat, measuring some 10 kilometres (6.2 mi) long. The original earthwork was later reinforced and faced with brick and stone resulting in 2 m (6 ft 7 in)-thick ramparts.

The citadel was oriented to face the Hương River (Perfume River) to the southeast. This differs from Beijing's Forbidden City, which faces true south. Rather than concentric rings centered on the emperor's palace, the imperial residence itself is offset toward the southeast side of the citadel, nearer the river. A second set of tall walls and a second moat were constructed around this Imperial City, within which many edifices were added in a series of gated courtyards, gardens, pavilions and palaces. The entire complex was the seat of power until the imposition of the French protectorate in the 1880s. Thereafter it existed mostly to carry on symbolic traditions until the Nguyễn dynasty was ousted in 1945, with the Proclamation of Independence of the Democratic Republic of Vietnam. The abdication ceremony of Emperor Bảo Đại took place at the Imperial City on 30 August 1945.

In its prime, the Purple Forbidden City had many buildings and hundreds of rooms. Once vacated, it suffered from neglect, termite ravages, and inclement weather including a number of cyclones. Most destructive were man-made crises, as evidenced by the bullet holes still visible from the military conflicts of the 20th century.

Major losses occurred in 1947 when the Việt Minh seized the Citadel in February. The French led counter-attack operations where they laid siege and engaged in a six-week ensuing battle which destroyed many of the major structures. The core of the city, including the Imperial Palace, was burned.

The Citadel came under fire again in the early morning of January 31, 1968. As part of the Tet Offensive, a Division-sized force of the People's Army of Vietnam and Viet Cong soldiers launched a coordinated attack on Huế, seizing most of the city. During the initial phases of the Battle of Huế, due to Huế's religious and cultural status, United States Marines troops were ordered not to bomb or shell the city, for fear of destroying the historic structures; but as casualties mounted in house-to-house fighting, these restrictions were progressively lifted and the fighting caused substantial damage to the Imperial City. Viet Cong troops occupied some portions of the citadel while South Vietnamese troops occupied others; and allied warplanes targeted the anti-aircraft guns the communists had mounted on the citadel's outer towers. Out of 160 buildings, only 10 major sites remain after the battle, such as the Thái Hòa and Cần Thanh temples, Thế Miếu, and Hiển Lâm Các.

The city was made a UNESCO World Heritage site in 1993 as part of the Complex of Huế Monuments. The buildings that remain are being restored and preserved. The latest, and so far largest, restoration project was planned to conclude in 2015.

The grounds of the Imperial City are protected by fortified ramparts 2 by 2 kilometres (1.2 by 1.2 mi), and ringed by a moat. The water in the moat is routed from the Hương River through a series of sluice gates. This enclosure is the citadel (Kinh thành).

Inside the citadel is the Imperial City (Hoàng thành; 皇城), with a perimeter wall some 2.5 kilometres (1.6 mi) in length.

Within the Imperial City is the Purple Forbidden City (Tử cấm thành; 紫禁城), a term identical to the Forbidden City in Beijing. Access to the innermost enclosure was restricted to the imperial family.

The Citadel have 10 gates include:

• Chính Bắc gate (more familiar as cửa Hậu (Back gate), located at the back of the Citadel).
• Tây-Bắc gate (more familiar as cửa An Hòa (An Hoa gate), named after the village here).
• Chánh Tây gate
• Tây-Nam gate (more familiar as cửa Hữu (Right gate), at the right side of the Citadel).
• Chính Nam gate (more familiar as cửa Nhà Đồ (Nha Do gate), because nearby there is Vo Kho - a warehouse for storing weapons, established during Emperor Gia Long period).
• Quảng Đức gate
• Thể Nhơn gate (more familiar as cửa Ngăn (Blocked gate), because in the past, there was a high wall blocking the emperor's path to the riverbank.).
• Đông-Nam gate (more familiar as cửa Thượng Tứ (Thuong Tu gate) named after the Thuong Tu Institute - the agency that raises and trains the royal and emperor's horses. At the same time, the emperor's cavalry and carriages were stationed. That's why the gate is named like that - "Thuong" (is superior, is what belongs to the emperor), and "Tu" (is a four-wheeled carriage pulled by horses) ).
• Chính Đông gate (more familiar as cửa Đông Ba (Dong Ba gate), name of residential area here ).
• Đông-Bắc gate (more familiar as Cửa Kẻ Trài (Ke Trai gate) )
• In addition, the Citadel also has a gate connecting with Tran Binh Dai (sub-citadel -a bastion in the Northeast corner of the Citadel, also known as Mang Ca citadel), called Tran Binh Mon (Tran Binh gate)
• Two gates by waterway connecting the Citadel with the outside through the Ngu Ha system are Dong Thanh Thuy Quan (east citadel water gate) and Tay Thanh Thuy Quan (west citadel water gate)
• In the middle of the front of the Citadel is a flag tower, called Ky Dai.

• Ngọ Môn (午門) (South gate)
• Hòa Bình Môn (和平門) (North gate)
• Chương Đức Môn (彰德門) (West gate)
• Hiển Nhân Môn (顯仁門) (East gate)

• Thái Hòa Điện (太和殿, Hall of Thái Hòa) ( The throne hall was built in 21/2/1805 and was rebuilt in 1833 and moved to the current location.)
• Phụng Tiên Điện (奉先殿, Hall of Phụng Tiên ) The palace is used to worship Emperors and Queens of the Nguyen Dynasty. Unlike The Mieu, this palace also worships the Emperors and Empresses of the Nguyen Dynasty, but women in the court are allowed to come here to worship.
• Trường Sanh Cung (長生宮, Trường Sanh palace) The palace's original role was a royal garden, where the Nguyen Dynasty Emperors invited their mothers to visit and enjoy the scenery. Later, the palace was converted into living palace for a number of Queen Mothers and Grand Queen Mothers
• Diên Thọ Cung (延壽宮, Diên Thọ palace) The residence of the Queen Mothers or Grand Queen Mothers of the Nguyen Dynasty

• Triệu Miếu (肇廟)Temple worshiping Nguyen Kim- Founder of the Nguyen clan and father of Nguyen Hoang -the first lord of Cochinchine- Đàng Trong (17th–18th centuries). Trieu To Temple was built during the reign of the first emperor of the Nguyen Dynasty, in the 3rd year of Gia Long (1804).
• Thái Miếu (太廟)Temple worshiping Nguyen lords, built in the 3rd year of Emperor Gia Long (1804)
• Hưng Miếu (興廟)Temple worshiping Nguyen Phuc Luan and Nguyen Thi Hoan-parent of the first Emperor Gia Long , built in the 3rd year of Emperor Gia Long (1804)
• Thế Miếu (世廟)The temple where the royal court came to worship the deceased emperors. Women in the court (including the queen) were not allowed to attend these ceremonies.
• Phụng Tiên Điện (奉先殿, Hall of Phụng Tiên ) The palace is used to worship Emperors and Queens of the Nguyen Dynasty. Unlike The Mieu, this palace also worships the Emperors and Empresses of the Nguyen Dynasty, but women in the court are allowed to come here to worship.
• Hiển Lâm Các (顯臨閣, Hien Lam Pavilion) is an architectural work located in the Hue urban complex, in the church area, built in 1821 and completed in 1822 under the reign of Emperor Minh Mang, along with The Mieu. Showing the areas located in the worship area in the Hue Imperial Citadel, it is 17 m high and is the tallest structure in the Imperial Citadel. This is considered a monument to remember the achievements of the Nguyen emperors and the great mandarins, generals of the dynasty.

• Đại Cung môn (大宮門, Great gate to enter Forbidden City) The gate has 3 doors, of which the main door is only for the Emperor. Currently, this royal gate has become a ruin due to being burned during the Viet Minh resistance campaign in February 1947 .This building is being restored, expected to be completed in 2028
• Tả Vu (左廡, Left hall), Hữu Vu (右廡, Right hall) Ta Vu is the building for literary mandarins, while Huu Vu is the building for martial mandarins; This is where mandarins prepare ceremonies before holding and where Thi Đình (Palace exam) and royal banquets are held. Ta Vu and Huu Vu were both built in the 18th year of Emperor Gia Long (1819)
• Cần Chánh Điện (勤政殿, Hall of Cần Chánh) (Working office of emperor, rebuilt in 1827, 1850, 1899) where the emperor held daily court, working, received diplomatic envoys, and held royal and court banquets of the Nguyen Dynasty. In the palace, in the middle of the main house, the throne is placed. On the columns on both sides are hung mirror paintings showing the beautiful scenery of the capital and maps of the provinces in the country. The palace is also a place to display many treasures of the Nguyen Dynasty such as rare Vietnamese porcelain, golden and jade royal seal of the dynasty. Currently, this palace has become a ruin due to being burned during the Viet Minh resistance campaign in February 1947, this building is being restored, expected to be completed in 4 years from 2024.
• Võ Hiển Điện (武顯殿, Hall of Võ Hiển)
• Văn Minh Điện (文明殿, Hall of Văn Minh)
• Trinh Minh Điện (貞明殿, Hall of Trinh Minh)
• Quang Minh Điện (光明殿, Hall of Quang Minh)
• Càn Thành Điện (乾成殿, Hall of Càn Thành) This palace is the living place of the Emperor of the Nguyen Dynasty. When the Emperor passed away, the coffin stayed here until the funeral. Can Thanh Palace is also a place to stored many treasures such as rare porcelain items as well as Royal Seals made of gold and jade; royal metal books; a casket containing a golden royal genealogy; national history books ; official dispatches, documents; maps. This palace has become a ruin due to being burned during the Viet Minh resistance campaign in February 1947
• Khôn Thái Điện(坤泰殿, Hall of Khôn Thái) (Residential palace of Empress consort, demolished in Khai Dinh's era)This is the residence of the Queen and Empress of the Nguyen Dynasty
• Thuận Huy Viện (順徽院)
• Dưỡng Tâm Viện (養心院)
• Ngự Tiền Văn phòng (御前文房, Office of cabinet)
• Lục Viện (六院, Six institution)This is the residence of the royal concubines of the Nguyen Dynasty.
• Minh Thận Điện (明慎殿, Hall of Minh Thận )

• Thiệu Phương Viên(紹芳園, Royal garden) built in 1828 during

the reign of Emperor Minh Mang Vườn Cơ Hạ (chữ Hán: 幾暇園, Peace Garden) built in 1837 during the reign of Emperor Minh Mang

• Kiến Trung Lâu (建忠樓) (Kien Trung palace, Main residential palace of Emperor and family in 1923 until the end of dynasty)
• Thái Bình Lâu (太平樓) (Reading room of emperor)

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  The citadel's plan in the Đại Nam nhất thống chí. The diagram is oriented with south at the top
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  The scene of medical treatment for the royal family in the Thái Y Viện
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  Enthronement of Emperor Bảo Đại in the Imperial City in 1926 with the Emperor's palanquin escorted from Hall of Diligent Governance (Điện Cần Chánh) to the Throne Hall
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  Aerial view of the Imperial City in Hue during the feast in honor of the takeover of Emperor Bảo Đại, 11 September 1932
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  Walls of the Meridian Gate
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  Meridian Gate
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  Tripod cauldrons of the Nguyễn dynasty
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  Gate
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  Flag Tower of the citadel
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  Gate of Chương Đức (彰德門)
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  Pavilion of Splendour (Hiển Lâm Các, 顯臨閣)
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  Pleasure garden in the residence of the imperial queen-mother. Hòn non bộ is installed in the lake
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  Courtyard before the Great Palace (Điện Thái Hòa) gate, with entrances to Càn Thành Hall (Điện Càn Thành) flanking both far sides of the photo
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  Flowerbed before an archway leading to Phung Tien Palace (Điện Phụng Tiên,奉先殿)

• 5182931945 Imperial City of Huế on OpenStreetMap
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