Seikan Tunnel Museum

The Seikan Tunnel connects Honshu and Hokkaido under the Tsugaru Strait, and the museum in Sotogahama documents the 24-year construction effort that built it. Workers began in 1964 and completed the undersea crossing in 1988, navigating geological faults, flooding, and shifting volcanic rock at depths of up to 240 meters below sea level. Exhibits display original engineering equipment, cross-section models of the tunnel structure, and photographs of the workforce. Interactive panels walk through the decision-making behind the route and the scale of the challenge.