Entrance of mining tunnel
Otaniyama mine, Yamada-machi, Shimohei District, Iwate Prefecture, Japan
Entrance of mining tunnel in Otaniyama Mine.
Field observation in May, 2015.
This tunnel is, perhaps, Kouryu-adit or Shinsei-adit located in south slope of Nekoi-sawa (Nekoi-valley).
© Hiroaki TANO