Weiyuan Fortress, Zhenhai, Coastal fortified town in Zhenhai District, Ningbo, China.

Weiyuan Fortress is a fortified site near Ningbo that stretches roughly 360 meters along the water with stone walls and gun emplacements. The structure shows clear military planning through its crossed platform design and multiple cannon positions meant to repel sea attacks.

Weiyuan Fortress was built in 1560, during the Ming Jiajing reign, by commander Lu Tang and sea-route deputy commissioner Tan Lun to resist Japanese pirates. Four iron cannons and over 40 barracks were added in 1562. The walls were expanded in 1665 and repaired in 1832. In October 1841 British forces captured the fortress, and it was heavily damaged and rebuilt in 1845.

The name reflects its role as a coastal guardian, and the layout shows how communities once defended their ports and trade routes. The gun positions reveal how important this location was for controlling maritime passage.

The fortress stands on the summit of Zhaobao Mountain, reached on foot via paths and stairs, so sturdy shoes help on the uneven stone paving inside the walls. The enclosure is rectangular, 502 metres around, with gates at the northeast and southwest; the gate plaque reads "Weiyuan City" in the calligraphy of magistrate Guo Chunzhang (1832).

The gun positions were specifically arranged to target ships moving through the narrow strait, a technically clever solution for its era. This design reveals how precisely planners understood and countered threats from sea traffic.