Battle of Nanshan /
南山の戦い - Nanzan no tatakai/ took place on 24–26 May 1904 across a two-mile-wide defense line across the narrowest part of the Liáodōng Peninsula, covering the approaches to Port Arthur and on the 116-meter high Nanshan Hill, the present-day Jinzhou District, north of the city center of Dalian, Liaoning, China.
On 24 May 1904, during a heavy thunderstorm, the Japanese Fourth Division under the command of Lieutenant General Ogawa Mataji attacked the walled town of Chinchou (modern-day Jinzhou District 金州), just north of Nanzan hill. Despite being defended by no more than 400 men with antiquated artillery, the Fourth Division failed on two attempts to breach its gates. Two battalions from the First Division attacked independently at 05:30 on 25 May 1904, finally breaching the defenses and taking the town.
With his flank thus secure, General Oku could then commence the main assault on the entrenched Russian forces on Nanshan Hill. The assault was postponed a day due to the weather. On 26 May 1904, Oku began with prolonged artillery barrage from Japanese gunboats offshore, followed by infantry assaults by all three of his divisions. The Russians, with mines, Maxim machine guns and barbed wire obstacles, inflicted heavy losses on the Japanese during repeated assaults. By 18:00, after nine attempts, the Japanese had failed to overrun the firmly entrenched Russian positions. Oku had committed all of his reserves, and both sides had used up most of their artillery ammunition.