Archaeologists in central China's Henan Province have discovered six tombs dating back to the Tang Dynasty (618-907) between two buried ancient city walls at different depths, shedding light on ancient site studies with multiple cultural layers in the Yellow River basin.

This photo taken on March 25, 2023 shows a Tang Dynasty (618-907) tomb discovered at the Songguogucheng site, or the ancient capital ruins of the State of Song in the Spring and Autumn Period (770-476 BC), in Shangqiu, central China's Henan Province. (Xinhua/Li An)

This photo taken on March 25, 2023 shows a bronze coin unearthed from a Tang Dynasty (618-907) tomb at the Songguogucheng site, or the ancient capital ruins of the State of Song in the Spring and Autumn Period (770-476 BC), in Shangqiu, central China's Henan Province. (Xinhua/Li An)

An archaeologist works at a Tang Dynasty (618-907) tomb discovered at the Songguogucheng site, or the ancient capital ruins of the State of Song in the Spring and Autumn Period (770-476 BC), in Shangqiu, central China's Henan Province, March 25, 2023. (Xinhua/Li An)

An archaeologist works at a Tang Dynasty (618-907) tomb discovered at the Songguogucheng site, or the ancient capital ruins of the State of Song in the Spring and Autumn Period (770-476 BC), in Shangqiu, central China's Henan Province, March 25, 2023. (Xinhua/Li An)

This photo taken on March 25, 2023 shows epitaphs unearthed from a Tang Dynasty (618-907) tomb at the Songguogucheng site, or the ancient capital ruins of the State of Song in the Spring and Autumn Period (770-476 BC), in Shangqiu, central China's Henan Province. (Xinhua/Li An)

This photo taken on March 25, 2023 shows clay jars unearthed from a Tang Dynasty (618-907) tomb at the Songguogucheng site, or the ancient capital ruins of the State of Song in the Spring and Autumn Period (770-476 BC), in Shangqiu, central China's Henan Province. (Xinhua/Li An)