Nakayama Zuido
Nakayama Tunnel (Hepburn: Nakayama zuidō) is unused tunnel on National Route 291 in Niigata, Japan. It is located at between Naganuma and Uonuma. Its length is 922 m and this is longest hand‐cut tunnel in Japan. It made in between 1933 and 1949 by residents in Komatsukura settlement (Komatsukura chiku), old Yamakoshi Village. In 1998, new tunnel for vehicles was opened and old tunnel have been preserved as historic site. It is known that construction of new tunnel was involved with Kakuei Tanaka. There is a documentary film named "Horumaika Tebori Nakayama-Zuido no Kiroku " directed by Shinichi Hashimoto. It is designated on Civil Engineering Heritage Sites Selection by Japan Society of Civil Engineers in 2006.
Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).