Introduction to Xitai Castle: Xitai Castle is located on the south coast of Wai'an Village, Penghu County, Taiwan Province, southwest of Xiyu Island. It is also called Li Hongzhang Castle because it was built by Li Hongzhang in the Qing Dynasty to prevent pirates. The fortress is entirely covered in basalt layers, with thick walls and wide tunnels that can accommodate 54 garrison troops. It is currently listed as a first-class historic site. At the end of the castle is a sea cliff with obvious erosion terrain. There are camping areas nearby for accommodation. The ticket price is 25 yuan for individuals and 20 yuan for groups; the castle opening hours are: 8:30-16:30.