Anfeng Tang, Ancient reservoir in Shou County, China.

Anfeng Tang, also called Shaobei, is a reservoir in the Huai River basin at Shou County, Anhui. Its earth dam was built with soil, wood and straw, and after dredging in 1978 it holds about 66.77 million cubic metres of water. The reservoir is still in operation and irrigates the surrounding farmland.

The system was built during the Spring and Autumn Period, when Chancellor Sunshu Ao of the Chu State directed the dam construction between 598 and 591 BCE. This early engineering achievement marked a milestone in ancient Chinese water management projects.

The reservoir is also called Anfeng Tang, while the older name Shaobei means "peony flower". Local accounts credit its construction to Sunshu Ao, chancellor of the state of Chu; since the 1970s some scholars argue it cannot predate the Han dynasty. The reservoir still supplies irrigation water in the Huai River basin.

The location is best explored when water levels are visible and pathways around the structure are dry, typically during cooler months. Comfortable walking shoes are recommended as the terrain is uneven and stretches lack shade.

The dam was built from soil, wood and straw, not stone, and the reservoir was first called Shaobei, meaning peony flower. Some scholars since the 1970s argue construction could not predate the Han dynasty, so the 585 BC date is disputed. After dredging in 1978 it holds 66.77 million cubic metres.