The Eternal Golden Castle (Chinese: 億載金城), alternatively but less well known as Erkunshen Battery (二鯤鯓砲台), is a defensive castle in Anping District, Tainan, Taiwan.

The castle was built in 1874 and completed on 1876 by the famous Qing official Shen Baozhen in order to safeguard the coast and to defend the island against Japanese invasions. This military facility saw its first action in the Sino-French war of 1884. When Taiwan was ceded to the Empire of Japan by the Qing in 1895, the Taiwanese people fought under the Republic of Formosa banner against the invading Japanese battleships from this fortress. Under Japanese control this military facility lost its value. Its value is completely lost when during the Russo-Japanese War the imperial Japanese government sold some of the fort's cannons.

There is a park near the castle grounds where people can enjoy picnics, as well as rental paddle boats for people to sail around the castle. There are occasional music performances in the evening, and actors sometimes fire the last remaining artillery gun in the castle to give visitors a fully immersive experience.

By driving: Take the Yongkang Interchange (Exit 319) of Freeway 1 and head in a south-westerly direction.

By public transport: Take the TRA to Tainan Station, and then take buses 2, 7, 12, and 20 to Ximen bus stop. Then take bus 15 to Miaoshouli, and you should be there in a few minutes.

There is a NT$70 fare for each visitor.

• List of tourist attractions in Taiwan
• Ershawan Battery
• Fort Zeelandia
• Fort Provintia
• History of Taiwan

• Bender, Andrew et al. (2004). Taiwan. San Francisco: Lonely Planet.