Hakkoda Tunnel

The Hakkoda Tunnel is a massive railway tunnel located in Aomori Prefecture on the northern tip of Japan's main island. It runs directly through the treacherous Hakkoda Mountains, providing a direct path for bullet trains.

When it opened in 2010, the tunnel allowed the Tohoku Shinkansen line to successfully extend its high-speed rail service all the way to Shin-Aomori Station. This drastically reduced travel times between Tokyo and the northernmost prefectures of Honshu.

The impressive engineering structure stretches for approximately 26.5 kilometers, making it one of the longest land tunnels in Japan. Its massive length was necessary to completely bypass the heavy snowfall and steep gradients of the Hakkoda mountain range.

Construction was notoriously difficult due to massive volumes of underground hot water and soft, faulted rock deep within the mountains. Engineers had to constantly deal with boiling mud and high-pressure steam, which tragically resulted in worker casualties during excavation.