The Soul Altar is a ritualistic structure established by the Nguyễn dynasty to commemorate the brave citizens and soldiers who sacrificed their lives during the significant event known as the "Fall of the Imperial Capital" on the 23rd day of the 5th lunar month in the year Ất Dậu (1885). Through historical documents, it can be affirmed that the Soul Altar serves as both a "National " and a "People’s Altar" symbolizing the resistance against French colonialism in Vietnam. This place holds great importance in Vietnamese history, bearing witness to the patriotic spirit, anti-colonial struggle, and noble values of the nation.

Every year, the people of Hue hold ceremonies to honor the souls of those who sacrificed their lives during the events of the Fall of the Imperial Capital. These rituals embody profound human values and contribute to creating a distinctive cultural identity that is unique to the land of Hue.

Due to its significant historical and cultural value, the Soul Altar site was designated as a provincial-level historical and cultural relic by the Provincial People's Committee according to Decision No. 2568/QD-UBND dated November 26, 2013.

In July 2023, the Thua Thien Hue province decided to restore and refurbish the Soul Altar relic. The restoration is planned to be carried out over a period of two years on a land area of more than 1,100 square meters. The project will be overseen by the Center for the Conservation of Hue Ancient Capital's Heritage, with an estimated total investment of over 8.8 billion Vietnamese dong.

According to the "Đại Nam thực lục" (The Chronicles of Đại Nam), on the 23rd of May, 1885, the Imperial City of Hue fell to the French forces' attack, resulting in the death of thousands of soldiers and civilians in the chaos of the battle. The Soul Altar was established by the Nguyen dynasty in 1894, nine years after the events of the Fall of the Imperial Capital (on the 23rd of the 5th lunar month in the year Ất Dậu - 1885). It was created as a place to commemorate the bravery and resistance of the citizens and soldiers who refused to surrender to the oppression of the French colonialists. Every year on the 23rd of the 5th lunar month, the Nguyen dynasty held ritual ceremonies at this Soul Altar.

The Soul Altar was constructed at the location where a large-scale ambush took place, led by high-ranking officials Tôn Thất Thuyết and his younger brother, with the aim of attacking and defeating the reinforced French forces. However, the ambush ultimately failed. In the aftermath of the battle, all of the royal soldiers were killed. Some of them were thrown into the river by the French, while others were burned, causing a persistent foul odor to pervade the city. Subsequently, the area became plagued with unrest, frequent fires, and insecurity. Rumors started circulating among the population that the spirits of the fallen soldiers were causing the fires due to the lack of proper worship. To pacify the populace, in 1894, the Hue dynasty established a  dedicated to the fallen soldiers, known as the "Đàn âm Hồn."

Initially, the Soul Altar was made from earth, but later it was built using more permanent materials to become a place of worship. Within the Soul Altar, there is a plaque commemorating the soldiers who sacrificed their lives during the Fall of the Imperial Capital. Additionally, the dynasty added a three-compartment house to store offerings and related artifacts. They also established a small caretaker team to look after the Soul Altar.

During the monarchy era, on the day of the ritual, Lady Từ Cung had soldiers carry offerings to the Soul Altar. Various officials from within the Inner City also participated in the ceremony. When the offerings and monetary contributions were abundant, the organizing committee would provide cattle and pigs for the ceremony.

At that time, the "Lễ tế Đàn âm Hồn" (Ceremony of the Đàn âm Hồn) was considered a national ritual, and the Imperial Regent of the Imperial City was the presiding officiant. This ritual persisted until 1945. After 1945, due to the dissolution of the Nguyen dynasty, the Soul Altar was no longer protected as before. The structures of the Soul Altar gradually deteriorated due to war and human interference. Nevertheless, the local population continued to uphold the worship of the Soul Altar through the establishment of Phổ Phước Lợi (a community devoted to the ) with the participation of around 100 households.

The restoration and ceremonious organization of the "Lễ tế Đàn âm Hồn" contribute to highlighting the value of the historical relic and preserving the spiritual and cultural beauty of the people of the Ancient Capital of Hue.

The Âm Hồn ceremony was restored and solemnly held at the Soul Altar, contributing to promoting the value of the relic and preserving the cultural and spiritual beauty of the people of Hue (Photo: Ngoc Bich)

Acknowledging the importance of the Soul Altar, the local authorities and the direct management unit, the Center for the Conservation of Hue Ancient Capital's Heritage, officially recognized the Soul Altar as a provincial-level historical and cultural relic on December 15, 2013.

For the first time in May 2018, the "Lễ tế Đàn âm Hồn" was held in accordance with the traditional ritual of the dynasty on this historical site and has been maintained as a ceremonious event up to the present day.

According to Vietnamese historians and those from Thừa Thiên Huế province, the Altar holds both a "National " and a "People's " significance. It stands as a historical relic of great importance not only for the nation as a whole but also for the region of Thừa Thiên Huế. It is closely connected with a significant event in the nation's history, the Fall of the Imperial Capital.

Alongside the Đàn Nam Giao and Đàn Xã Tắc, the Altar represents a religious architectural legacy from the Nguyen era in Hue. It is considered the first martyr, symbolizing the patriotic spirit and resistance against foreign colonization by the Vietnamese people during the late 19th century.

Throughout its existence of over 100 years, the Altar relic has been closely intertwined with the spiritual and cultural activities of the people of Hue. Especially during the Nguyen dynasty - the last feudal dynasty of Vietnam - the "Lễ tế Đàn  m Hồn" was regarded as a national ceremony and was upheld until 1945. After 1945, due to the collective sentiment of the Nguyen dynasty, the protection of the Soul Altar diminished. The structures of the Soul Altar gradually deteriorated due to the impacts of war and human interference. Nonetheless, the practice of worshiping at the Soul Altar has continued to be maintained by the local population through the establishment of Phổ Phước Lợi (a community dedicated to worship) with the participation of around 100 households. Additionally, an annual ceremony is organized on the 23rd day of the 5th lunar month.

From the city center of Hue, travel across Phu Xuan Bridge, then take a left onto Lê Duẩn Street. Proceed straight ahead, passing through the Ky Dai relic, Phu Van Lau, and Nghinh Luong Đình, then make a right turn into Cửa Quảng Đức Street. After passing through the gate, turn left and follow the wall of the Imperial City of Hue in a westerly direction for about 200 meters. You will arrive at the address of the Soul Altar  (73 Ông Ích Khiêm Street, Hue City).