☆Connecting Lines through the Generations: Imafukusen Junction In order to connect Hamada and Hiroshima through the Imafukusen line, a new line starting from Hamada Station, and an old line whose starting point was Shimoko Station, were constructed. However, neither were fully built, and the overlapping of the two created a junction. Shimokogawa Bridge One was the new line, and the Four Arch Bridge the old; the crossing of two lines from different generations is a rare sight to see in Japan. Ahead of Shimokogawa Bridge One is the Shimonagaya Tunnel, which was built in 1975. With a length of 1633 meters, it is the longest tunnel included within the remnants of the Imafukusen line. Shimonagaya Tunnel is very unique. The walls of the entrance are perpendicular to the ground, and they evolve into a horseshoe shape when going towards the exit, making both sides very different to one another.