I got to experience the Tokyo Bay Aqualine Tunnel and it is mind-blowing. The Trans-Tokyo Bay Highway, also known as the Tokyo Bay Aqualine, is a 15.1 km marine crossing through the middle of Tokyo Bay connecting Kawasaki City in Kanagawa Prefecture with Kisarazu City in Chiba Prefecture on the Boso Peninsular. The Aqualine consists of a 9.5-km shield tunnel (the Tokyo Bay Tunnel) and a 4.4-km bridge from an artificial island to the Kisarazu landing. The tunnel diameter is the world's largest for an underwater shield tunnel used for motor vehicle traffic. The cross-section diameter to the outside of the segment lining is 13.9 m, and the inner diameter of 11.9 m provides for two lanes of traffic in both directions. It is also considered one of the most amazing roads to travel on in the world.
Obviously, I did not photograph this aerial pic but just wanted to show the magificient architecture of this tunnel/bridge.