The Ministry of Culture, Sports and Tourism has granted permission to the Center for Conservation of the Ho Dynasty Citadel Heritage (Thanh Hoa) in collaboration with the Institute of Archaeology to conduct the largest-ever archaeological excavation at the Nam Giao altar site in Tay Do.

W-a1Khai quật Đàn tế Nam Giao hơn 600 năm.jpg
An overview of the Nam Giao altar area prior to excavation.

Nguyen Van Long, Deputy Director of the Center for Conservation of the Ho Dynasty Citadel Heritage, said this is the most extensive excavation ever undertaken at the site.

The project is expected to reveal more historical and cultural values buried beneath the former imperial capital of the Ho Dynasty.

This initiative also reflects Thanh Hoa Province’s commitment to UNESCO in preserving and promoting the value of the World Heritage-listed Ho Dynasty Citadel.

From October 2025 to July 2026, the excavation will cover nearly 10,000 square meters, including 94 excavation pits across two key areas: Platform 4 and Platform 5. These are critical zones within the architectural layout of the Nam Giao altar.

Nguyen Van Long emphasized that all authorized parties must ensure the safety of stratigraphy, artifacts, and the excavation site.

They are required to follow the timeline, objectives, and regulations set by the Ministry of Culture, Sports and Tourism. All discovered artifacts will be preserved in situ, scientifically documented, and reported for appropriate conservation or exhibition planning.

“We hope this excavation will provide valuable scientific evidence to support research and the reconstruction of sky-worship ceremonies conducted by the Ho Dynasty, thereby enhancing the historical significance of the Ho Dynasty Citadel World Heritage Site,” said Long.

W-a2Khai quật Đàn tế Nam Giao hơn.jpg
The altar zone under active excavation.

W-a3Khai quật Đàn tế Nam Giao hơn.jpg
An ancient well inside the altar grounds.

W-a4Khai quật Đàn tế Nam Giao hơn.jpg
The foundations within the Nam Giao altar begin to emerge.

Historical records show that in 1400, King Ho Quy Ly founded the Ho Dynasty and relocated the capital to Tay Do (now in Vinh Loc District, Thanh Hoa).

In 1402, King Ho Han Thuong ordered the construction of the Nam Giao altar as the ceremonial site for imperial worship of heaven and earth.

Completed in August the same year, the altar spanned over 2 hectares and was located about 2.5 kilometers southeast of the Ho Dynasty Citadel.

Since 2004, there have been four preliminary surveys and excavations covering nearly 18,000 square meters. These efforts have helped archaeologists identify the key characteristics of the relic.

The Nam Giao altar features five ascending platforms and faces south, embodying the ancient Chinese-Vietnamese cosmological belief in “round heaven, square earth.”

The entire structure was built with green stone, the same signature material used to construct the Ho Dynasty Citadel.

Archaeologists have also discovered numerous terracotta artifacts, such as rectangular bricks, leaf-shaped roof tiles embossed with dragon motifs, and other relics reflecting advanced craftsmanship and aesthetic sensibilities of the era.

The altar's foundations are gradually being revealed through the excavation.

The Nam Giao altar was classified as a provincial heritage site in 1990 and elevated to national archaeological site status in 2007.

It is one of three core zones that make up the Ho Dynasty Citadel World Heritage Site, alongside the Inner Citadel and the royal tomb area.

The entire complex was officially recognized as a UNESCO World Heritage Site in 2011.

Le Duong