Following the Battle of Jiuliancheng at the Yalu River, and subsequent minor engagements in the Liaodong Peninsula, the strategic aim of Japan was to seize the heavily-defended and strategically important naval base of Lüshunkou, known in the West as "Port Arthur". This naval station had taken the Qing government sixteen years to build, and was considered superior to Hong Kong in its facilities. Defended by its hilly terrain and strengthened with fortifications and powerful artillery, it was widely considered to be an impregnable stronghold. Lüshunkou was also the only facility with dry docks and modern equipment capable of repairing the warships of the Beiyang Fleet, and its loss would mean that China would no longer have the capability to repair any ship damaged in combat. The location of Lüshunkou, at the entrance to the Gulf of Bohai also meant that it controlled the sea approaches to Beijing.