A piece of relic discovered at the Neolithic ruins at Taoyuan, a village in the city of Linfen, Shanxi province. [Photo by Zheng Yuan/Provided to China Daily]

"Such a big building perhaps was an office for a tribe leader or a public venue for meetings or worship ceremonies of a major tribe," he said, adding it was the first of its kind found in Shanxi Province.

Previously, a dozen prehistoric pentagonal buildings had been found in China, mainly located in Lingbao City, Henan Province.

The discovery is part of findings from an excavation that began in August in Taoyuan, a village in Jiade Township of Linfen's Yaodu District, to prepare for highway construction in the area, said Zheng Yuan, excavation team leader of the project.

Zheng said the total excavation area is 2,500 square meters, and aside from four house ruins, they have also discovered ruins of a pottery kiln and unearthed a variety of pottery pieces.

She said the excavation is important for researching society and life in the Miaodigou Culture, the most powerful period in prehistoric China, which was centered around the provinces of Shanxi, Shaanxi and Henan.