Located in Fengshan Hill crossing over Linyuan, Daliao, Fengshan Districts, the tunnel is a defense base built manually by residents of Linyuan, Daliao, and Siaogang recruited by Japanese military, as an effort to prevent landing of U.S. forces. It’s known as the underground Great Wall and was the greatest defense engineering in scale during the Japanese Colonial Period in Taiwan, dating back 60 years. The main tunnel begins at Fengshan Reservoir, passing Cingshueiyan Scenic Area to reach Siaogang Fengpitou, stretching more than 10 kilometers. The winding narrow tunnel allows only one person to pass at a time, while its branch is complex in structure. Inside the cave sees rich seabed resources which of great value in terms of culture and history. Remains of a conference room, a kitchen, beds and others evidence Kaohsiung’s southing position during the Japanese Colonial Period. Currently, tunnels of Longpan Cave are safer for visiting. Visitors are strongly recommended to be fully equipped before setting out.