A major archaeological discovery in East China's Shandong province has filled a critical gap in the history of China's salt production, confirming a 2,000-year-old tradition of extracting salt from brine along the Bohai Sea coast.

The Pojiazhuang salt-making site in Dongying, covering 89,000 square meters and located about 20 kilometers from the sea, was excavated from 2024 to 2025. 

Archaeologists uncovered over 60 circular brine wells from the Northern and Southern Dynasties (420–589) — the first such discovery from this era in the region. These wells, measuring 8 to 10 meters in diameter and 1.5 meters in depth, were reinforced with bundled reeds and wooden stakes — a simple yet effective technique that demonstrates the ingenuity of the craftsman at that time.

An aerial photo of a brine well (left) from the Northern and Southern Dynasties (420–589) period is unearthed in Dongying, Shandong province; Right: Details of the wells and tools. [Photo/WeChat account: sdswltwx]

Two complete salt-making workshops from the Jin (1115–1234) and Yuan (1271–1368) dynasties were also unearthed in the northeastern part of the salt-making site. Featuring brine wells, boiling stoves, brine channels, and clay pits, the site provides a complete picture of the entire production process from brine extraction to boiling and salt crystallization.

The discovery confirms that the "brine well digging, drawing, and salt boiling" method used in northern China's Bohai coastal region has continued uninterrupted for over 2,000 years, from the Shang and Zhou dynasties (c.16th century–256 BC) through the Jin and Yuan periods. 

This stands in contrast to the "scraping brine from tidal flats" method and the "evaporating sea water" method practiced in southern China at the same time — revealing two parallel salt production traditions that together shaped the country's ancient maritime salt industry.

A stove used to extract salt from brine was carbon dated back to the time of the Jin (1115–1234) and Yuan dynasties (1271–1368). [Photo/WeChat account: sdswltwx]