#00447 / Transport
Longest Railway Tunnel with an Undersea Section
Verified53.85km
Seikan Tunnel
Beneath the Tsugaru Strait, between Aomori and Hokkaido, Japan
Japan's Seikan Tunnel runs beneath the Tsugaru Strait between Honshu and Hokkaido. Its 53.85 km total length includes 23.30 km beneath the seabed; the record concerns total length of a tunnel containing an undersea section, not the longest undersea segment.
