The conclusions were been listed among China's top 10 archaeological findings of 2002 by the Chinese Society of Archaeology.

Through the excavation of the Xigu relics in Helong City, in the northeastern province of Jilin, archaeologists discovered the remains of the capital of the Bohai Kingdom, which prospered in the Tang Dynasty (AD 618-907) and then mysteriously disappeared.

Bohai Kingdom was a vassal state (AD 698-926 ) of the Tang Dynasty, founded mainly by the Mohes, a minority ethnic group in northeast China at the time and the predecessors of the Manchus.

At its peak, with Shangjing (the upper capital) in Heilongjiang ' s Longquan Prefecture as one of its five capitals, the kingdom covered large areas which included parts of present-day Heilongjiang and Jilin provinces.

Located 15 kilometers from Helong City, the relics revealed that the city had double ramparts. The outer rampart was 720 meters long and 630 meters wide, and the inner rampart was 310 meters long and 190 wide. Most parts of the ancient city are now farmland.

Archaeologists said the scale and architecture of the ancient city, named Zhongjing (central capital) at the time, made it a rival to the other two key capitals of the kingdom, Shangjing and Dongjing (east capital).

Song Yubin, deputy director of the institute of archaeology of Jilin, said the findings have rectified previous incorrect hypotheses and encouraged new research on the kingdom with the use of a newly drawn map of Xigu city based on the recent excavation.

(eastday.com April 18, 2003)