The Longest Undersea Tunnel In The World

The "Seikan Tunnel" in Japan is the longest undersea tunnel in the world, stretching **53.85 kilometers (33.5 miles)**, with approximately **23.3 kilometers (14.5 miles)** running beneath the seabed. Opened in **1988**, it connects the islands of "Honshu" and "Hokkaido"" via the **Tsugaru Strait**. The tunnel accommodates high-speed trains, including the iconic Shinkansen, and was built to withstand harsh weather and seismic activity, providing a safe and reliable transportation link.