Archaeologists have found ruins of a pentagonal structure dating back 5,500 years in the city of Taiyuan, north China's Shanxi Province. 

The remains, unearthed at a construction site in Taiyuan, Shanxi's provincial capital, are believed to belong to the middle and late periods of the Yangshao Culture, according to the Taiyuan Institute of Cultural Relics and Archaeology.

A total of 98 ash pits, 11 pottery kilns, two houses and six tombs of Ming (1368-1644) and Qing (1644-1911) dynasties were found at the site, among which the most prominent discovery was the pentagonal house covering about 32 square meters, said Pei Jingrong, a researcher with the institute. 

Abundant pottery pieces have been unearthed in the house, including sand-filled pottery kettles, sand-filled grey pottery pots, red pottery pots, and sharp-bottomed bottles, Pei said. 

The discovery is of great academic value for studying the cultural features of the Neolithic Age in Taiyuan Basin and the prehistoric cultural exchanges in Taiyuan and its surrounding areas, according to experts. 

Originating around the middle reaches of the Yellow River, the Yangshao Culture is considered an important stream of Chinese civilization and is widely known for its advanced pottery-making technology.