After the southbound train leaves the Shengsing Train Station, it then goes downhill to enter the Tunnel No.2. This 726-meter tunnel was built in 1905. It was not greatly damaged by the earthquake in 1935, therefore it did not go through major renovation and the original brick structure remains. Traces of Chinese calligraphy “Kai Tian” written by Goto Shimpei, a Japanese officer who laid the foundation for the industrial development in Taiwan, can still be seen at the north side of the tunnel close to Shengsing Station. The unused barracks on the slope was originally military camps during the martial law period. 

It is a highly accessible tunnel, and thus becomes a popular attraction for those who go to visit the Shengsing Train Station. Many tourists try to enter the tunnel for adventures or to experience its mystiques.