Massive Underground Flood Diversion Channel in Japan

Cavernous concrete tunnel with evenly spaced columns diverting floodwaters in Japan.

Cavernous Flood Diversion Tunnel in Saitama, Japan

Vast underground concrete tunnel with evenly spaced columns stretching into the distance, dimly lit by spotlights casting pools of light on the reflective floor, part of Japans Metropolitan Area Outer Underground Discharge Channel to divert floodwaters during heavy rains.