Ershawan Battery (), or better known as Tenable Gate of the Sea () is a battery emplacements camp in Zhongzheng District, Keelung, Taiwan. It was built during Taiwan's Qing era, and was the site of combat between the French and Chinese forces during the Sino-French War. It was the command post of Liu Ming-chuan, who was later appointed by Qing court as the first governor of Taiwan, when he was charged with the defense of Keelung during the war. It lost its military value under Japanese rule, and is currently listed as a class one national historical monument.