Tianchang Tunnel

This abandoned tunnel cuts through Tianchang Cliff (天長斷崖) along a Taipower access road in the upper Mugua River basin deep in the mountains of Xiulin, Hualien. Taipower dug the 1,270 meter-long passage in 1978 as part of the Qilai Water Diversion Project (奇萊引水工程), bypassing the unstable surface route of the old Nenggao Traversal Road (能高越嶺道) used during the Japanese colonial period. The tunnel is the longest marble-walled tunnel in Taiwan, with no concrete lining and no lighting, leaving the raw stone exposed and glimmering when illuminated. A collapse in the middle section has since rendered it impassable to vehicles, and the wider Qilai route is closed to all but Taipower and Forestry Bureau personnel.