Located in Chenggong Township, Taitung, the Xiaoma Tunnel is a ground-level road tunnel that cuts through the magnificent Coastal Mountain Range, connecting Provincial Highway 11 and Provincial Highway 23. Dating back to the Japanese colonial period and the post-war era, the tunnel has witnessed the transportation and agricultural development of the Taiyuan Basin. Stretching about 230 meters in length, it allows only single-lane traffic. The tunnel walls retain the traces of manual excavation from the past, and walking inside feels like stepping back in time to a bygone era.