Liuheng Island (六橫島) is located off the coast of Zhejiang province in China. It served as a significant maritime location during the 16th century, primarily known for hosting the port of Shuangyu.
During the Ming dynasty, when private overseas trade was prohibited, Shuangyu functioned as an illegal entrepôt and smuggling hub. The port attracted international traders from Portugal, Japan, and Southeast Asia. Portuguese sources referred to the location as Liampó, a name derived from the nearby mainland city of Ningbo.
The island's period as a pirate haven and illicit trading center began around 1524. This era concluded in 1548 when the Ming navy destroyed the port. While historical accounts of its destruction were significantly exaggerated by the Portuguese travel writer Fernão Mendes Pinto, the site remains a notable point in regional maritime history.