Upstream of a pretty stone bridge, the right bank of Yamakuni River is home to this unusual tunnel. Some 340m/1,120ft long, it was dug from 1735 over a thirty-year period by a Buddhist monk called Zenkai. Armed with a chisel and hammer, he wanted to create a safer access to the neighbouring Rakan-Ji temple than the dangerous cliffside climb used at the time. The tunnel has since been restored, but a large portion of the original gallery remains, cleverly lit by small openings cut into the rock.