[The World's 20 Most Amazing Tunnels]Tokyo Bay Aqua Line, Japan

 

 

 

It took more than three decades of design work and construction to build the Tokyo Bay Aqua Line, a roughly 8 1/2-mile-long bridge and tunnel system that carries traffic both over and under Japan's Tokyo Bay between the cities of Kisarazu and Kawasaki. (Hideyuki KAMON/flickr.com)