All of these copper cauldrons are of substantial size and weigh from several hundred to a few thousand catties. At present, within the gardens of the Đại Nội area in Huế, there are seven large copper cauldrons cast during the 17th century under the Nguyen lords' rule over Đàng Trong. In terms of design, size, age, and artistic decorative style, these seven cauldrons can be divided into two groups.
1. Group of cauldrons cast during the Trịnh-Nguyễn conflict period:
This group consists of three cauldrons: one in front of the Kiến Trung Palace, cast in the seventh year of Thịnh Đức (1659); one in front of the Tả Vu House, cast in the eighth year of Thịnh Đức (1660); and one in front of the Hữu Vu House, cast in the tenth year of Thịnh Đức (1662). These cauldrons all have an upright body, wide flared mouth, and raised handles, with four handles attached to the rim. The decorative arrangement features horizontal bands encircling the cauldron. From the top downward, there are nine bands separated by raised ridges. Bands 3, 4, 6, and 7 are narrower, while bands 1, 9, 2, 5, and 8 are wider, adorned with continuous undulating vine motifs forming a closed loop. The wider bands 2, 5, and 8 are the main decorative elements, divided into equal-sized rectangular compartments by vertical straight lines, each compartment showcasing unique floral patterns. The floral decoration forms a complete circle on the band 5 of the cauldron in front of the Kiến Trung Palace. These three cauldrons are nearly equal in weight and size. The cauldron in front of the Tả Vu House is slightly larger, weighing 2582 catties (Vietnamese measurement); it has a mouth diameter of 2.2m, an interior diameter of 1.83m, and a height of 1.05m (including the 1.30m-high handles). The decorative style of enclosed horizontal bands was popularized in Đông Sơn culture, featuring wave-like vine motifs that create a dynamic rhythm.
The decorative motifs include flowers, leaves, birds, and animals. The cauldron cast in 1695 features only flowers and leaves, while the two cauldrons cast in 1660 and 1662 also include birds and animals. The birds and animals on the cauldron from 1660 move counterclockwise, but on the cauldron from 1662, there's a depiction of a creature moving in the opposite direction.
2. Group of cauldrons cast towards the end and after the Trịnh-Nguyễn conflict:
This group consists of four cauldrons, including three dating back to the Cảnh Trị era and one to the Chính Hòa era. The cauldron cast in 1670 is only 8 years after the late cauldron from the previous group, but its design, arrangement, size, and decorative motifs are entirely different, indicating a new direction in development. The two cauldrons cast in 1762, one located on the left side of the Thái Hòa Palace and the other on the right side of the Càn Thành Palace, as well as the cauldron cast in 1684, also on the Càn Thành Palace but on the left side, are the remaining pieces from this group.
Patterns and motifs on the cauldron at the same time Lord Nguyen placed in the Citadel - Hue
This group of four cauldrons varies slightly in size, but their design is entirely uniform. The largest cauldron in this group, located at the Càn Thành Palace, weighs 1390 catties (Vietnamese measurement), has a mouth diameter of 1.69m, and a height of 0.94m. The cauldrons in this group have an upright body that slightly tapers outward, with a mouth that flares out almost perpendicular to the cauldron's body. The base is flat, and there are four pairs of handles attached vertically, almost perpendicular to the cauldron's body and close to the rim. The overall design is reminiscent of a ceramic or porcelain flowerpot, with decorative motifs covering about one-third of the exterior surface from the rim downwards. The neck of the cauldron is adorned with a band of 24 undulating vine motifs, except for 8 motifs which are inverted to accommodate the handles. Within this band, 4 inverted and 12 upright vine motifs depict flowers, leaves, or birds and animals. Beneath the vine band is a row of "lá sòi" motifs, with each leaf featuring five dots. In many places, the recognizable floral motifs include lotus, chrysanthemum, and plum blossom. In terms of the motion of the birds and animals, the cauldron cast in 1670 features eight birds, seven of which move counterclockwise while one flies in the opposite direction. In the cauldron cast in 1672, the movement of birds and animals seems random, with some moving clockwise and others counterclockwise. The cauldron located behind the Thái Hòa Palace, also cast in 1672 but six months later, shows all the birds moving clockwise, and no animals are present. The cauldron cast in 1684 has neither animals nor birds, only floral and leaf motifs. Over time, the engravings on these four cauldrons become coarser.
In general, these seven cauldrons, cast between 1659 and 1684, are encapsulated within the reign of Emperor Nguyễn Phúc Tần, also known as Hiền Vương. This period coincided with the country's involvement in the Trịnh-Nguyễn conflict from 1627 to 1672, leading to the division into Đàng Trong and Đàng Ngoại regions. All seven cauldrons are marked with the historical era of the Lê dynasty kings and maintain a consistent artistic style. There are, however, certain "novel" elements possibly due to local influences, the expertise of craftsmen from Đàng Trong, and perhaps even the involvement of Western copper casting experts.
The bronze cauldron was cast in 1631 during the reign of Lord Nguyen Phuc Nguyen (1613 - 1635), weighing 339kg, and shaped like a large pot now located at the Museum of Royal Antiquities in Hue
The bronze cauldron was cast in 1677 during the reign of Lord Nguyen Phuc Tan (1648 - 1687), weighing 560 kg (equivalent to 338 kg) and located at the Museum of Royal Antiquities in Hue
The bronze cauldron is placed in the middle of the courtyard, in front of the Ngung Hy Palace, and the tomb of King Dong Khanh was cast in 1673 under the reign of Hien Vuong Nguyen Phuc Tan (1648 - 1687).
Among the 11 copper cauldrons, there are 2 largest and heaviest cauldrons that are not only exquisitely decorated but are also considered some of the most remarkable artifacts not only within the Nguyen Dynasty but also in the entirety of Vietnam, even up to the present day. These two cauldrons are prominently placed in front of the Cần Chánh Palace. Both of these copper cauldrons were cast during the reign of Emperor Nguyễn Phúc Tần (1648 - 1687). The cauldron on the left was cast in 1660, weighing 1,552kg, while the cauldron on the right was cast in 1662, weighing 1,489kg. The shape and architecture of these two cauldrons are very similar; both have handles, stand at a height of 1m, and have a wide mouth diameter of 1.2m. The body of each cauldron is divided into 60 equal sections, separated by vertical lines. Each section is meticulously carved with intricate depictions of animals, plants, and objects, including celestial bodies, flowers, leaves, birds, and animals.
All of these cauldrons were officially recognized as National Treasures in 2015.