Six metres of archaeological layers beneath Kinh Thien Palace contain evidence spanning roughly 1,300 years of Thang Long’s history. The 2026 excavation has revealed remains from successive Vietnamese dynasties, including major foundations associated with Kinh Thien Palace and the later Nguyen Dynasty’s Long Thien Palace.Image credit : VIETNAM NEWS
The Discovery
Archaeologists excavating the Kinh Thien Palace site within the Thang Long Imperial Citadel in Hanoi have uncovered what researchers describe as the deepest and most complete archaeological stratigraphic sequence of Thang Long-Hanoi’s history identified to date.
The findings were presented at a scientific seminar organised jointly by the Thang Long-Hanoi Heritage Conservation Centre and the Institute of Archaeology, where researchers reported preliminary results from the latest excavation season.
The 2026 excavation is the fourth conducted at the site and covers approximately 910 square metres in the area of a former artillery building.
Combined with three previous excavations, the work has exposed around six metres of archaeological stratigraphy.
The oldest identified layer dates to approximately 1,300 years ago, providing evidence of human activity long before the surviving imperial palace structures.
Instead of representing a single period of occupation, the sequence contains archaeological material associated with successive political eras, creating a physical record of the changing capital.
The excavation has also exposed substantial architectural remains from two important palace phases: the Nguyen Dynasty’s Long Thien Palace and the earlier Kinh Thien Palace.
What Archaeologists Found
The excavated sequence contains evidence attributed to multiple periods:
- Dai La period: 7th–9th centuries
- Dinh and Early Le Dynasties: 10th century
- Ly Dynasty: 11th–12th centuries
- Tran Dynasty: 13th–14th centuries
- Early Le Dynasty: 15th–16th centuries
- Revival Le period: 17th–18th centuries
- Nguyen Dynasty: 19th century
The sequence provides a continuous archaeological framework through major stages of Thang Long-Hanoi’s history.
Among the most important architectural discoveries are traces of Long Thien Palace, a Nguyen Dynasty structure built under Emperor Gia Long.
The exposed column foundations and drainage channels correspond with the east-west boundaries of the former French colonial artillery building.
The new evidence also clarifies the results of an excavation conducted in 2025.
Researchers concluded that Long Thien Palace followed a distinctive Nguyen Dynasty architectural arrangement in which a front hall and main hall shared the same foundation, with the two buildings connected by an intervening roofed section.
Beneath Long Thien Palace, archaeologists encountered remains associated with Kinh Thien Palace, dating to the Early Le and Revival Le periods.
Historical Background
The archaeological layers at the site reflect the long development of Thang Long, the historic imperial capital represented today by the Thang Long Imperial Citadel.
Rather than being rebuilt on an empty landscape each time political circumstances changed, successive periods left physical traces within the same urban and architectural environment.
The excavation demonstrates this particularly clearly.
The six-metre sequence contains evidence from the Dai La period through the Nguyen Dynasty, spanning approximately thirteen centuries of human activity.
Kinh Thien Palace belongs to the Early Le and Revival Le phases represented in the sequence.
Historical records indicate that the palace's building platform was not simply formed from the natural ground. Instead, the area was artificially constructed, with clay and construction materials carefully deposited and compacted before the positions of the structural foundations were established.
This preparation created a substantial platform capable of supporting the palace's large architectural components.
The later construction of Long Thien Palace placed another major architectural phase above the remains associated with Kinh Thien Palace.
Scientific Analysis
The archaeological importance of the excavation lies heavily in the stratigraphic sequence and the relationship between successive architectural remains.
Researchers recorded approximately six metres of deposits containing material from multiple historical periods. Because the layers occur one above another, archaeologists can examine changes in occupation and construction across different phases of Thang Long's development.
The structural remains of Kinh Thien Palace are particularly notable for their scale.
The excavated column bases include single and double foundations.
Single foundations measure approximately 2.8–3.5 metres by 2.5–3.5 metres.
Double foundations measure approximately 5.4–6.1 metres by 2.7–3 metres.
The column bases were constructed on additional foundation structures.
Researchers describe them as the largest and most technically sophisticated column foundations yet identified in the history of Vietnamese architecture.
The exposed foundations have also allowed archaeologists to reconstruct the palace's basic layout.
From east to west, Kinh Thien Palace appears to have contained nine bays with 10 rows of columns.
Its north-south arrangement consisted of five bays with six rows of columns.
These measurements provide a physical framework for understanding the scale and organisation of the palace.
Why This Discovery Matters
The excavation matters because it connects architectural remains with a much broader sequence of urban history.
The six-metre stratigraphy is not simply a deep archaeological deposit. It records successive periods ranging from the Dai La period to the Nguyen Dynasty.
That makes the excavation especially valuable for examining how the imperial centre developed over time.
The foundations associated with Kinh Thien Palace provide another important line of evidence.
Their dimensions, construction techniques and arrangement reveal the considerable engineering effort involved in creating the palace platform and supporting its columns.
The identification of nine bays and 10 column rows in the east-west direction, together with five bays and six rows north-south, also provides researchers with a clearer picture of the building's architectural organisation.
Meanwhile, the Long Thien Palace remains show how the site continued to be used and transformed during the Nguyen Dynasty.
How many more architectural phases might still be preserved beneath the surviving layers of Thang Long?
The question remains open because the excavation has exposed only part of a much larger archaeological landscape.
What’s Next?
The 2026 excavation represents the fourth archaeological investigation at the Kinh Thien Palace site.
Researchers will continue analysing the excavated stratigraphy, architectural remains and artefacts to refine the chronology of activity at the site.
Particular attention will be given to the relationship between the Kinh Thien and Long Thien Palace remains.
The new evidence from the column foundations has already helped clarify findings from the 2025 excavation, demonstrating the value of continuing archaeological work in the area.
Further excavation and analysis may provide additional information about the construction and layout of the imperial buildings represented within the six-metre sequence.
The wider objective is to build a clearer archaeological understanding of the long development of Thang Long-Hanoi's historic capital.
Conclusion
The latest excavation at Kinh Thien Palace has exposed an extraordinary archaeological sequence extending approximately six metres beneath the modern surface.
Its oldest identified layer dates to around 1,300 years ago, while successive deposits preserve evidence from the Dai La period through the Nguyen Dynasty.
The foundations of Kinh Thien Palace provide particularly important evidence of large-scale Vietnamese architectural engineering, while the remains of Long Thien Palace demonstrate the site's continued transformation during the Nguyen Dynasty.
Together, the discoveries provide a physical record of more than a millennium of activity at one of Vietnam's most important historic urban sites.
FAQ
How old are the archaeological layers at Kinh Thien Palace?
The deepest identified archaeological layer dates to approximately 1,300 years ago. The six-metre sequence contains remains from several successive historical periods.
How deep is the archaeological sequence?
The excavations have revealed approximately six metres of archaeological stratigraphy. It contains evidence ranging from the Dai La period to the Nguyen Dynasty.
What was discovered beneath Long Thien Palace?
Archaeologists found traces of Kinh Thien Palace beneath the remains of the Nguyen Dynasty's Long Thien Palace. The earlier structure dates to the Early Le and Revival Le periods.
How large were the Kinh Thien Palace foundations?
Single column foundations measured approximately 2.8–3.5 metres by 2.5–3.5 metres, while double foundations measured about 5.4–6.1 metres by 2.7–3 metres.
