This undated file photo shows a pottery pot unearthed at the Sidun Site in Tianning District of Changzhou, east China's Jiangsu Province. (Nanjing Museum/Handout via Xinhua)

Forty tombs, some stilt-style buildings, and wells, dating back to about 4,500 years to 5,500 years ago, have been recently found in Changzhou City, east China's Jiangsu Province.

The ruins, with multiple relics, including pottery, jadeware, and stoneware, were discovered at the Sidun Site in today's Tianning District of Changzhou.

The site is centered on an oval mound, surrounded by more than 10 small flat foundations and moated by dual water systems. According to the Nanjing Museum, the total area is about 1.5 million square meters.

The museum and its researchers have carried out excavation work at the site since 2019.

Researchers believe that the Sidun Site reflects the changes from the late Songze Culture to the Liangzhu Culture and provides a new perspective for studies on the development model of regional civilization in the lower reaches of the Yangtze River in ancient times.

"More than 5,000 years ago, the Yangtze River Delta region already belonged to the same cultural circle," said Yu Chenglong, associate researcher of the Nanjing Museum, adding that the Sidun Site vividly reflects the complicated formation and development of prehistoric society in the Taihu Lake area, and helps reveal the process of the local development toward the early state form.

This undated aerial file photo shows the Sidun Site in Tianning District of Changzhou, east China's Jiangsu Province. (Nanjing Museum/Handout via Xinhua)

This undated file photo shows relics discovered at the Sidun Site in Tianning District of Changzhou, east China's Jiangsu Province. (Nanjing Museum/Handout via Xinhua)