Yi Tzai Golden Castle (Eternal Fortress)

The Yi Tzai Golden Castle, or Eternal Fortress, was built in 1876. It was built by a Qing official who believed that certain strong military defense mechanism should be constructed to protect Tainan City from invasion of foreign troops, such as those from Japan. Later, during the Sino-French War in 1884 and before Taiwan was ceded to Japan as a colony in 1895, the fortress demonstrated its seaside defense utility. Both foreign troops dared not enter the area.

The fortress was designed by a French engineer, and was the first port equipped with British Armstrong Cannon in Taiwan. It symbolized a significant step toward modernization of Taiwan's coastguard military defense. Configured in Western-styled brick construction, the fortress appears in a square structure with cannon towers at its four corners. The concave center courtyard is designed for military drills. The fortress's outer walls are about two meters high, while the arched entrance gate is five meters tall.

The fortress has been designated as a first grade historic site. Outside the fortress's outer walls is a moat that used to run contain sea water. Inside the fortress, there are cannons, small dunes made of clay for the protection of cannons and gunners, and bastions and counter-forts for transporting ammunitions.