The defense system of Hoa Lu capital city has been unearthed.

GD&TĐ - The results of archaeological excavations of the Dền citadel in Ninh Bình province at the end of May 2025 revealed a system of interconnected ramparts that played a crucial role in the defense of the ancient Hoa Lư capital.

Excavation site of the Dền city wall in 2025.

The hypothesis is that Champa prisoners built the Den citadel.

The Ninh Binh Department of Culture and Sports , in collaboration with the Vietnam Institute of Archaeology, recently organized a workshop to present the preliminary results of the excavation of the Dền citadel site located in Chi Phong village, Truong Yen commune, Hoa Lu city.

According to the Hoa Lu Ancient Capital Historical and Cultural Relics Conservation Center, the Den citadel wall is an important archaeological site located north of the inner citadel area of ​​the Hoa Lu capital.

This is the outermost city wall, bordering the Hoang Long River, running in a northeast-southwest direction, connecting the two mountain ranges on the left bank of the river. This unique geographical location created a strong defensive system of ramparts, playing a crucial role in protecting the capital city.

The Citadel of Dền consists of two sections: The first section connects from Sau Cái Mountain (also known as Hàm Xà Mountain, Cổ Dải Mountain) to Cánh Hàn Mountain, and is the longest section of the citadel walls of Hoa Lư capital; the second section connects from Cánh Hàn Mountain to Hang To Mountain (Nghẽn Mountain).

In Decision No. 554/QD-BVHTTDL, the Ministry of Culture, Sports and Tourism authorized the Ninh Binh Provincial Department of Culture and Sports to cooperate with the Institute of Archaeology to excavate the Dền citadel wall from March 15th to May 30th, under the leadership of Dr. Nguyen Ngoc Quy - Institute of Archaeology.

During this excavation, experts opened two excavation pits. The first pit covered an area of ​​450 square meters, and the second was 150 square meters. The excavation process yielded many valuable specimens, including building materials such as bricks, stones, and clay; layers of plant matter, mollusk shells, as well as glazed ceramic artifacts from various periods.

At the same time, the Dền citadel walls revealed a three-part structure: foundation, body, and reinforcement layer. These revelations reflect the level of citadel construction techniques of the Vietnamese people at Hoa Lư in the 10th century. The artificial citadel walls at Hoa Lư were all built on weak, marshy soil. To overcome these geological conditions, the ancients used a technique of spreading plant stems along with reinforcement using wooden beams and driven stakes to prevent landslides.

The city walls typically have a semicircular or trapezoidal shape, with the outer slopes steeper than the inner slopes to increase structural support and stability. Two perimeter walls are built on this foundation to form the core of the wall, and a layer of white clay is placed on top. This white clay, originating from the sea, is known for its pliable nature.

In particular, through meticulous surveys and measurements, archaeologists believe that this section of the city wall was not excessively high compared to other areas. The reason is that outside the wall lies a large swampy area. The construction of the wall here reflects a conscious choice of location to enhance defense, creating a fortress that is "easy to defend, difficult to attack".

Based on the structure of the citadel, construction techniques, and collected artifacts, archaeologists hypothesize that the Dền citadel may be related to the war between the Lê dynasty and Champa. After their victory, the Lê dynasty captured Champa prisoners to serve in the construction of the citadel.

The foundation, body, and reinforcing layers of the Dền citadel walls were constructed using techniques characteristic of the 10th century.

Digitalization for heritage reconstruction

In addition to determining age based on structure and technique, scientists also rely on artifacts found such as broken bricks with inscriptions, glazed pottery fragments, and mollusk shells. Of particular note are some types of ancient inscribed bricks and the red-covered bricks commonly found at 10th-century sites.

According to Dr. Nguyen Ngoc Quy, the 2025 archaeological findings have supplemented and reinforced the data collected from previous excavations such as at the East Wall (1969), the exploration of the Den Wall (2018), and the emergency excavation of the Northeast Wall area. This data demonstrates a high degree of consistency in the wall construction techniques at Hoa Lu.

Not only did these excavations strengthen historical evidence and data, but they also confirmed that the interconnected and unified rampart system of Den Citadel had been formed, playing a defensive role for the Hoa Lu capital from the north.

Representatives from the Ninh Binh Department of Culture and Sports and the Vietnam Institute of Archaeology affirmed that the 2025 excavation was conducted in full compliance with modern archaeological procedures. Archaeological materials such as photographs and descriptive drawings have been carefully preserved. In particular, the excavation pits have been digitized using 3D scanning technology, serving the reconstruction and research in subsequent stages.

The Dền ramparts were a series of interconnected fortifications, serving as a defensive line for the Hoa Lư capital. Photo: Hoa Lư Ancient Capital Conservation Center.

The significant findings from the 2025 excavation of the Dền citadel wall have contributed to further research into the construction techniques, defensive organization, and dating and function of the Dền citadel wall within the system of fortifications protecting the Hoa Lư capital.

These research materials also serve as a basis for scientists to propose conservation and research plans for the relics in subsequent stages. At the same time, they provide a scientific basis for the restoration, preservation, safeguarding, and promotion of the heritage's value.

According to the Ministry of Culture, Sports and Tourism, following the completion of the excavation of the Dền citadel wall in May 2025, an expanded excavation will be conducted from June 11th to September 10th over a total area of ​​300m2, as requested by the Institute of Archaeology (Vietnam Academy of Social Sciences). The purpose of the expanded excavation is to study the foundations of the Dền citadel wall and moat to clarify the construction techniques, methods, and dates; and to understand the function and contribution of the Dền citadel to the overall ancient Hoa Lư capital.

Source: https://giaoducthoidai.vn/phat-lo-he-thong-phong-thu-kinh-do-hoa-lu-post735977.html