The Kanmom Straits, one of the entrances into the Seto Inland Sea, separate Honshu and Kyushu, and at its narrowest is only about 800 meters wide.
The Kanmon Bridge was one of the biggest suspension bridges in the world when it opened in 1973 to carry road traffic across the straits from Shimonoseki to Kitakyushu.
The central span is just over 1,000 meters. Prior to its construction there was a road tunnel beneath the water, as well as a tunnel for trains and even a pedestrian tunnel.
Ferries still connect the two sides as they have for centuries.