
Seikan Tunnel: The World’s Longest Undersea Railway Marvel Connecting Honshu and Hokkaido
Beneath the choppy waters of Japan’s Tsugaru Strait lies a feat of human engineering unlike any other—the Seikan Tunnel. Stretching an impressive 53.85 kilometers (33.5 miles), this undersea tunnel connects the islands of Honshu and Hokkaido and continues to hold the title of the world’s longest undersea railway tunnel more than three decades after its…