Guishan, originally named "Turtle Mountain," is located on the western side of Lieyu Lingshui Lake, and protrudes out from the southern coastline. The L19 outpost still quietly guards Guishan. Along the coastal area, there is a beautiful beach with a sandbar extending out to sea, forming a sandbar lagoon with a sandspit that turns back toward the land. The intertidal zone is rich in diverse marine life and ecosystems.