After the discovery of the inverted “品” shape ceramic drain pipes in the last century, archaeologists found a number of pottery drain pipes at Pingliangtai Ancient City ruins in central China’s Henan Province.

Experts believe that these pipes, dating back more than 4,000 years, are connected with drainage channels in an orderly manner, forming the earliest and most complete urban drainage system in China.

Discovered in 1980, the Pingliangtai site is the earliest and most complete prehistoric site in China and a pioneer in urban construction planning.

Archaeological excavations show that the city site is symmetrical in axis and square in layout, and suffered from internal flooding. Effectively draining the water in the city to the outside is believed to have always been a concern of people from that time.

A panoramic view of the Pingliangtai Ancient City ruins in Huaiyang, central China’s Henan Province. /Xinhua

A panoramic view of the Pingliangtai Ancient City ruins in Huaiyang, central China’s Henan Province. /Xinhua

Starting from 2014, Henan Provincial Institute of Cultural Relics and Archaeology and Peking University established a team to carry out a systematic excavation of the ancient ruins for six consecutive years.

The excavation shows that the drainage system covers the daily drainage of the city site, the drainage of the city wall and the gate passage.

The ceramic pipe is an important invention that appeared from the ancient city of Pingliangtai in the Neolithic Age in China. The ceramic water pipes unearthed from this site, whether in the city or in the city gates and walls, are all 35- to 45-cm long straight tube shape, with similar patterns on the surface.

Experts believe they are standardized, proving that the drainage system of the whole city is a public facility with unified planning and completed by social groups. It was a relatively developed scientific and cultural city at that time, and had an important academic research value.