Nabetachiyama Tunnel
The 112th longest tunnel in the world
Nabetachiyama Tunnel (Nabetachiyama tonneru) is a tunnel on Hokuhoku Line under Mount Nabetachiyama that runs from Oshima Ward, Joetsu city, Niigata prefecture to Matsushiro, Tokamachi city, Niigata prefecture with total length of 9.130 km. It was built and completed in 1997.
Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).