01 / Upper Iwabuchi Tunnel
Over about 10 km, with hard rock in places,a channel was cut in about ten years.

On a waterway west of the Nikaido residence in Shintomi is the Upper Iwabuchi Tunnel. The works, led by the magistrate Shimazu Zusho Hisamichi, opened paddies worth 2,000 koku in Shintomi and Nozaki villages. Begun in 1661 and finished in 1671, they are marked nearby by the stone monument Takayama Shinmizo-ki.
- 1661-1671
- Planned route about 10 km
- Paddies worth 2,000 koku

