The Chinese Academy of Social Sciences on Wednesday announced China's six top archaeological discoveries in 2009, including the discoveries of ruins of ancient paper-making workshops and the tomb of Chinese legendary general Cao Cao.

The ruins, spanning from Song Dynasty (960-1279) to Ming Dynasty (1368-1644), were located in the city of Gao'an in eastern Jiangxi Province

The site covered a total area of 700 square meters and were fully unveiled by the province's archaeologists in December in 2009, said Xiao Fabiao, a research fellow at the Jiangxi Provincial Institute of Cultural Relics and Archaeology.

"The discovery is significant," said Su Rongyu, a researcher at the Institute for History of Natural Science under the Chinese Academy of Sciences. "Because few relics of paper-making workshops had been uncovered before."

He also said the workshop ruins, where workers used to make paper from bamboo, were the earliest ones found in the country.

Paper, along with gunpowder, compass and movable type system are widely regarded as the four great inventions of ancient China. Paper-making in China was dated back to 150 A.D..

The ancient tomb unearthed in central China's Henan Province and confirmed by the CASS to be a burial place of the legendary General Cao Cao (155-220 A.D.).last month was also recognized by the institution as a top discovery.

The occupancy of the tomb was proven by its style, size, level, age and relics, especially inscribed objects. It was an established system adopted to identify many other ancient tombs in China, said Liu Qingzhu, a researcher with the academy.

The discovery is significant in that it will shed light on the evolution of burial customs and rituals in China, Liu said.

Other discoveries are the Lower Xiajiadian site of an ancient civilization between 2200 to 1100 B.C in Chifeng city in Inner Mongolia; the Neolithic ruins at Dongshan Village in Zhangjiagang, Jiangsu Province; the ruins of a city in Western Zhou Dynasty (1046-771 B.C.) in Chenzhuang Village in Gaoqing County, Shandong Province; the Lu-Clan burial grounds of Northern Song Dynasty at Wulitou in Lantian County, Shaanxi Province.

The top discoveries in 2009 were announced at the CASS Archaeology Forum, an annual academic forum on modern Chinese archaeology since 2002. The forum was jointly organized by the CASS, the Institute of Archaeology CASS and the Archaeology Press.

The Forum, a platform for the exchange of information on the latest archaeological discoveries and developments in China, was established with the aim of encouraging academic exchange and promoting the development of modern Chinese archaeology as a profession, said Wang Wei, head of the CASS Institute of Archaeology.