Enasan Tunnel is a tunnel on the Chūō Expressway (E19) in Japan that runs from Shimoina District, Nagano prefecture to Nakatsugawa City, Gifu prefecture with up-line length of 8.649 km and down-line length of 8.489 km. It was completed and opened in 1985.
Enasan Tunnel ⓘ The total length is 8,649m for the up line and 8,489m for the down line. When it opened in 1975, it was the longest road tunnel in Japan and the second longest road tunnel in the world. As of November 2017, it is the 6th longest tunnel after Yamate