創建
清同治十三年(1874)日本因牡丹社事件侵臺，清廷派沈葆楨來臺籌辦防務並派代表和日本交涉撤兵。另一方面積極加強防務，鑑於鞏固安平海防保護臺灣府城，建請建造砲台。利用熱蘭遮城磚材與洋式紅磚建造，四周有護河，引海水灌注，闊約十尺，水深沒頂，城門出入一座，開向東南。清光緒二年(1876)建竣，其不僅是臺灣第一座現代西式砲台，也配備五門英製阿姆斯脫郎十八噸前膛大砲，威力強大。砲位下有兩尺厚的三合土屋，作為避砲室和倉庫，昔已破壞，今改斜坡覆土。二十世紀初，大砲毀壞變賣，木橋斷陷，城洞砌磚封閉，一副殘破景觀。民國六十四年，砲台建成100週年時，臺南市政府大規模整建並仿製大砲、小砲，始成今貌。
History
In 1874, (the 13th year of Emperor Tongzhi’s reign in the Qing Dynasty) Japanese troops invaded Taiwan as a result of the Mudan Incident and prompting the Qing court to not only put Shen Baozhen in charge of Taiwan’s defense system, but also send a delegation to negotiate Japan’s military withdrawal from Taiwan. While vehemently reinforcing the Formosan defense works, Shen suggested that a fortress be built in Anping to safeguard the coastline and Taiwan Prefecture, present-day Tainan. Following his advice, the Eternal Golden Castle was constructed out of brick materials from Fort Zeelandia and European-style red bricks, encircled by an approximately 3-meter-wide moat filled with seawater deeper than the average height of adults. The castle was accessed through its southeastward-facing arched gate.
Inaugurated in 1876 (the 2nd year of Emperor Guangxu’s reign), the Eternal Golden Castle is Taiwan’s first modern, Western-style fortress equipped with powerful weapons: five British-made Armstrong muzzle-loading cannons that are 18-pounders. Beneath the cannon emplacements is the 60-centimeter-thick wall of a mortar house functioning as an anti-raid shelter and ammunition depot that, nevertheless, was destroyed and reduced to a soil-covered slope. Early in the 20th century, the castle was a sad sight of dilapidation as the damaged cannons were sold, wooden bridge broken and arched gate blocked off by fragmented bricks. Fortunately, replicas of cannons and guns were added to the Eternal Golden Castle in 1975 as part of Tainan City Government’s massive restoration effort that marked this historic site’s centenary.