The Praefect Department of the Northern Navy, also known as the Yamen of the Navy, was built in the 17th year of the reign period of Emperor Guangxu in Qing Dynasty (in 1891). It lies facing south on the southern slope of the western Liugong Island, with the sea in front and the hill at the back. It covers an area of 17,000 square meters. It is the first regular naval command organization in modern China. As a representative cultural site of the “Memorial Site of the Sino-Japanese War of Liugong Island”, it is one of the best-preserved military yamen in China.