During the ruling of the Qing Emperor Kuang Hsu, China and France had a war and signed a truce. The Qing government ordered magistrate Liu Ming-Chuan to build 10 fortresses to protect Taiwan from the harassment and attacks of pirates and bandits. Xiyu Western Fort was one of them. It is also the best-preserved and largest ancient fortress in Penghu, 8 hectares in area. The fortress is secure under thick rocks and spacious with a capacity of thousands of soldiers. It is not only a military base, but also has magnificent scenery.

Xiyu Western Fort has two arches in the entrance and the stone board on the out gate was inscribed by Li Hung Chang, a famous Qing official. There are many tunnels inside, leading to different chambers. The fortress has cliffs in the back, ocean in the front, which makes it perfectly secure. It also presents Penghu's peculiar position in history. Currently, it is classified as the first grade ancient site. Visitors to Penghu should never miss Xiyu Western Fort.