Xiuying Fort (秀英炮台), built in 1890 during the Guangxu reign on a 240-meter ridge in Haikou's Xiuying District overlooking the Qiongzhou Strait, was constructed in response to French naval threats following the Sino-French War and stands as one of the Four Great Coastal Forts of late Qing China, alongside Humen, Wusong, and Dagu Kou. 

The fort saw active use against Japanese forces in 1939, survived intact, and has since been designated a national key cultural relic in 2006, and today welcomes visitors for RMB 10 at the gate to explore its restored banyan-covered batteries, cool underground corridors, and a two-ton Krupp cannon — a 30–45 minute journey through one of China's most significant examples of late Qing coastal modernisation.