Dien Khanh Ancient Citadel

From Tay Nha Trang ward, take the 23/10 road to Dien Khanh commune, turn right onto Ly Tu Trong road, and proceed for about 500m to reach the East Gate of Dien Khanh Citadel.

Dien Khanh Citadel was built in Dien Khanh prefecture, serving as the local administrative center under the Nguyen Dynasty. Today, a portion of the original citadel remains, though its functions have changed significantly.

Looking back in history, migrants to new lands often chose to settle near rivers and streams for convenience in daily life, farming, and animal husbandry. The Vietnamese who arrived in the Thai Khang dinh area (later Binh Hoa dinh or Khanh Hoa province) primarily settled in the plains formed by large rivers: the Dinh River (Ninh Hoa) and the Cai River (Nha Trang, Dien Khanh). Along with the process of migration, land reclamation, and village establishment, the Nguyen Lords also built relatively stable and comprehensive political institutions, ranging from 'dinh' (military districts), 'phu' (prefectures) to 'thon' (villages) and 'sach' (hamlets), along with a team of officials and subordinates to manage and operate the affairs of the feudal state. However, from the mid-18th century onwards, the Nguyen Lords and some officials became conservative in their socio-economic policies and led luxurious, hedonistic lifestyles. To meet their needs, they increased taxes, and officials competed to exploit the people, leading to a life of hunger and hardship for the populace.

In 1771, the Tay Son uprising broke out, led by three brothers: Nguyen Nhac, Nguyen Hue, and Nguyen Lu, to oppose the rule of the Nguyen Lords. The harsh governance of the Nguyen Lords led the people of Dien Khanh to support the Tay Son movement. From 1773 to 1792, the people of Dien Khanh lived and worked peacefully under the Tay Son dynasty.

In 1775, after defeating the troops of Tong Phuc Hiep and Nguyen Khoa Thuyen at Tam Phong mountain (Co Ma pass, Van Tho commune, Van Ninh district), in order to strengthen southern defenses and turn this area into an important base for attacks on Gia Dinh, the Tay Son army built many outposts and fortifications in Khanh Hoa, such as: Trai Thuy hill, the Thuy Xuong area (Nha Trang), Hoa Chau (Dien Khanh), Du Lam (Ba Ngòi), Ninh Hai fortress, Hon Khoi outpost (Ninh Hoa), Tam Doc, and Son Tap (Van Ninh)...

In 1792, King Quang Trung passed away, and internal strife plagued the Tay Son dynasty. Nguyen Anh seized this opportunity to launch a counter-offensive to restore the dynasty. In the third lunar month of the Year of the Ox (1793), Nguyen Anh led his infantry to attack Phan Ri. “By the fifth month, the ships of Nguyen Vuong entered Nha Trang estuary, then marched up to capture Dien Khanh prefecture and Binh Khang prefecture."[1]. By the seventh month, Nguyen Anh’s troops had captured both Dien Khanh and Binh Khang prefectures. After examining the Dien Khanh administrative center, Nguyen Anh recognized it as a strategic location with convenient water (Cai River) and land transport routes from North to South, while also being near the Nha Trang estuary. He therefore ordered the construction of Dien Khanh Citadel as a fortified military base for long-term combat against the Tay Son army.

Nguyen Anh (later King Gia Long) ordered the construction of Dien Khanh Citadel in the area of two communes, Phu My and Truong Thanh, Phuoc Dien district, Dien Khanh prefecture, Binh Khang dinh, and assigned Nguyen Van Thanh to hold the defense. Afterwards, he ordered the relocation of the old dinh administrative center from Phuoc Da commune, Quang Phuoc district, Binh Khang prefecture, to Dien Khanh Citadel, which became the political and military center of Binh Khang dinh.

According to the book 'Dai Nam Nhat Thong Chi' (Comprehensive Geography of the Great South) by the Nguyen Dynasty's National History Institute, writing about the Khanh Hoa provincial citadel:
The perimeter is 636 truong, 7 thuoc, and 4 tac, with a height of 7 thuoc and 5 tac. It has 4 gates and a moat 4 truong wide and 6 thuoc deep, built of earth in the area of Phu My and Phuc Thinh communes, Phuc Dien district. Previously, the dinh administrative center was in Da Phuc commune, Quang Phuc district, then moved to the current location, which is the old Dien Khanh citadel – Note: Dien Khanh Citadel was formerly the Nha Trang outpost. In the Year of the Ox (1793), the King's troops marched to attack Quy Nhon. Upon returning, the royal procession stopped at Dien Khanh. Observing the terrain, he later ordered the construction of an earthen citadel on the old Hoa Bong site. The citadel had six gates, all with gate towers, and earthen hills at four corners; outside the citadel, a moat was dug, and outside the moat were camps; the gates all had drawbridges to cross the moat. Surrounded by mountains and rivers, it is truly a natural fortress; now two gates have been removed. The fortresses and earthen hills remain. To the north, the citadel backs onto the Cai River, which frequently caused flood damage, so in the 4th year of Minh Mang, an embankment was built across the river, and canals were dug to divert water to the north.[2]
According to 'Phuong Dinh Du Dia Chi' (Phuong Dinh's Geographical Treatise): "In the Year of the Ox, King The To Cao Hoang De recaptured that land, still called Binh Khang military post (establishing the roles of thi luu, cai ba, ky luc), and rebuilt Dien Khanh Citadel at the Nha Trang outpost; the mountains and rivers are truly a natural fortress, popularly called Nha Trang Citadel."[3]

Other historical documents record that Dien Khanh Citadel was built under the direct supervision of Prince Canh. The manpower used to build the citadel included 3,000 Binh Thuan soldiers and 100 Thuan Thanh civilians, and it was completed in just over a month. Dien Khanh Citadel served as a storage point for money and food transported from Gia Dinh and Binh Thuan for the Northern expeditionary army, which is why it was attacked by the Tay Son army many times.[4]

* The old Dien Khanh Citadel:
At the time of construction, the citadel was built on vacant land, shaped like a turtle, a sacred animal symbolizing longevity and stability. Outside was a system of deep moats. Inside, there were two sets of stairs for access. The corners of the citadel were built to protrude outward to facilitate observation on both sides. Inside each corner, a wide area was raised to serve as a troop shelter. At each corner of the citadel, an earthen mound about 2m high was built to mount cannons, known as corner bastions. This is a prominent feature of Vauban-style military architecture. Many bamboo and thorny trees were planted on the citadel to increase its durability and create a defensive barrier according to Vietnamese tradition. The moat system outside the citadel was between 3m and 5m deep, with varying width depending on the terrain. The bottom of the moat was usually filled with water and contained many obstacles. Outside the moat was an outer ditch. To enter the citadel, one had to cross a bridge over the water.

The fortress walls curved in a hexagonal shape, about 2,694m long and about 3.5m high. The outer face of the citadel was built slightly vertical, while the inner face was built with a gentle slope; there were stairs on both sides of the gates for access.

Each gate had a watchtower built so guards could see far ahead. At the corners, earthen mounds were raised to house defensive cannons; outside, near the foot of the citadel, was a defensive moat; outside the moat were military camps; and in front of each gate was an arched iron bridge to enter.

According to the Nguyen Dynasty cabinet, Dien Khanh Citadel was built in the 13th year of Gia Long (1814) from Phu Da to Phu My and Phuoc Thanh (or Truong Thanh). The new citadel had an irregular polygonal shape (turtle-shaped), with a perimeter of 2,679.83m, a height of 3.39m, and a moat of 19.08m. This time, there were only four gates in the four directions: East, West, South, and North.
In the 4th year of Minh Mang (1823), the left and right gates were filled in, leaving only four gates: East, West, Front, and Rear. On both sides of the gates, stairs were built to reach the top of the wall. Above the citadel gates were quadrangular pavilions with curved roofs covered in yin-yang tiles.

 * Dien Khanh Citadel today:
The four gates of the citadel were built identically. The gates have no elaborate decorations, only the names inscribed in Chinese characters: East Gate (門 東), West Gate (門 西), Front Gate (門 前), and Rear Gate (門 后). The gates were built of kiln-fired bricks measuring 4.5cm x 14cm x 28cm, plastered with lime mortar to form a block about 15m long. The central vault is 2.88m wide and 2.44m high, forming the passageway underneath.

The outer face of the citadel is built vertically, while the inner face has a brick wall 1.7m high and 5m long. The path on top of the citadel wall is 5.35m wide.
On both sides of the gates, 3m-wide stairs are built to access the top of the citadel gate. Above the citadel gate, a quadrangular pavilion is built with each side measuring 3.30m; the four openings in four directions are 1.30m wide and 2.5m high; at the top is the 'co lau' (upper floor) with a curved roof covered with yin-yang tiles. The upper floor is 4.1m high from the base. On either side of the quadrangular pavilion, railings 0.85cm high are built.

Connecting the four gates is a system of earth walls with a gentle slope on the inside and a slightly vertical face on the outside. The sections of earth wall are no longer seamlessly connected as they once were; the total length of the current earth wall is 1,656m, 3m high, and 5m wide on the surface.

People still walk through the citadel gates daily, except for the Rear Gate, which is located behind the kindergarten of Dien Khanh town.

Inside the citadel: Although Dien Khanh Citadel's structure follows the Vauban style, clearly shown in the citadel walls with the outer moat fortress system, the citadel gates and mansions built within were still in accordance with traditional Eastern architectural characteristics. According to some documents, there were previously architectural works such as: the Royal Palace, the office of the Governor, the Censor, the Military Commander, food warehouses, and a prison... all built according to Nguyen Dynasty court regulations and following Vietnamese architectural styles.

Within the area of the 974th Regiment unit, there is still a cannon resting on a gun platform. The cannon is placed on the vacant lot in front of the Regiment's gate. In addition, there is an abandoned shrine here. The book 'Dong Khanh Du Dia Chi Luoc' (Abridged Geographical Record of Dong Khanh), in the 'Shrines' section of Khanh Hoa, records: "Inside the provincial citadel is the Thien Y Shrine of Thien Y Thanh Nuong"[5]. Today, only four walls of the shrine remain, and on top are Chinese characters on a scroll plaque reading "Thanh Phi Mieu" (Holy Consort Shrine), dated the 6th year of Bao Dai (1931). In 'Xu Tram Huong' (Land of Agarwood) by Quach Tan, there is a mention of the legend of the Three Sisters shrine, but today this shrine no longer exists. After surveying and researching, we discovered one remaining corner of the shrine's wall located behind the 974th Regiment base (part of the Khanh Hoa Provincial Military Command) and it has been covered by overgrown trees.

Currently, the citadel houses the headquarters of agencies in Dien Khanh district, such as: the Dien Khanh Party Committee, the People's Council and People's Committee of Dien Khanh district, the Confederation of Labor... and schools: Phan Chu Trinh Secondary School, Dien Khanh Town Primary School, Hoa Phuong Kindergarten... along with several residential groups of Dien Khanh town.

* Some typical historical events that took place at Dien Khanh Citadel:
1. The battles between the Tay Son army and the Nguyen Dynasty army at the end of the 18th century;
2. The command center of the Can Vuong (Save the King) movement in Khanh Hoa, led by Trinh Phong (1885-1886);
3. The place where the patriotic intellectual Tran Quy Cap was detained during the final days of his life (1908);
4. The uprising to seize power during the August Revolution in 1945 and the inauguration ceremony of the Provisional Revolutionary People's Committee of Dien Khanh prefecture;
5. In the first lunar month of 1946, Comrade Vo Nguyen Giap conveyed the "Resistance and National Construction" directive of the Central Committee and relayed Uncle Ho's inquiries and praise for the fighting spirit of the people of Nha Trang – Khanh Hoa.

Over time, the citadel has become mossy, and many sections of the earth walls and moats have eroded. In 2003, Dien Khanh Citadel was renovated, the four gates were painted, and areas with cracked walls or rainwater leakage, as well as several sections of the citadel wall, were reinforced. In 2010, the Khanh Hoa Department of Culture, Sports and Tourism carried out a project to restore Dien Khanh Citadel and zone off protected areas to embellish and promote the value of the relic.

Recognizing the historical and cultural values of the Dien Khanh Ancient Citadel relic, on November 16, 1988, the Ministry of Culture issued Decision No. 1288/VH-QĐ, ranking it as a National Historical-Cultural Relic.

Some images of Dien Khanh Ancient Citadel:

West Gate of Dien Khanh Ancient Citadel


Rear Gate of Dien Khanh Ancient Citadel

East Gate of Dien Khanh Ancient Citadel

Front Gate of Dien Khanh Ancient Citadel

Surface of the Dien Khanh Ancient Citadel wall

[1] Tran Trong Kim 1999, Viet Nam Su Luoc (A Brief History of Vietnam), p.421.
[2] Nguyen Dynasty National History Institute. Dai Nam Nhat Thong Chi (2006), Volume 3, Book XI, p.107.
[3] Nguyen Van Sieu 2001. Phuong Dinh Du Dia Chi, p.265.
[4] Phan Khoang 2001. Viet Su Xu Dang Trong (History of the Dang Trong Region), p.541.
[5] Hinh Phuoc Lien, Nha Trang Magazine (6/2016), No. 249, Dong Khanh Du Dia Chi Luoc (Section on Khanh Hoa province - part 1), pp.74-80.

Source: https://disanvanhoa.khanhhoa.vn/