Lüshunkou (旅顺口), or Lüshun Port, is a southernmost district of Dalian City of the People's Republic of China. Surrounded by ocean on three sides, this strategic seaport was called Port Arthur during the Russian Occupation and Ryojun (旅順) during the Japanese one. Port Arthur took its name from a British Royal Navy Lieutenant named William C. Arthur. In August 1860, during the Second Opium War, Arthur had towed his crippled frigate into the harbor at Lüshun (at that time an unfortified fishing village) for repairs.
The Japanese-controlled Ryojun City had 40 districts. The communist Lüshun City was established on November 25, 1945 to replace Ryojun. The city was a subdivision of a larger Lüda City and contained 40 villages in 3 districts: Dazhong (大众区), Wenhua (文化区), and Guangming (光明). In January 1946, Wenhua was merged into Dazhong, and the 40 villages were reduced to 23 communes (坊). In January 1948, the remaining two districts were merged into one: Shinei (市内区), with 12 communes.
On January 7, 1960, Lüshun City was renamed Lüshunkou District, still under Lüda. In 1985, 7 of its 9 townships were upgraded to towns.
Lushun is situated on the southern tip of Liaodong Peninsula and in the western most part of Dalian.
Lushun occupies an area of 244.22 square kilometers and is the largest scenic place in Dalian with 8 scenic areas and 72 scenic spots.
The site of the former Lushun Prison, which was established by Tsarist invaders and later expanded by the Japanese aggressors, covers a ground area of 226,000 square meters.