Aonodōmon

Aonodōmon (青の洞門, meaning "blue tunnel") is a tourist attraction located in the gorge of Yabakei, now part of Nakatsu City, in Ōita Prefecture, Japan.

The path was very dangerous and people regularly fell to their deaths.

During the Edo period, a Buddhist monk named Zenkai, who had committed a murder in his earlier life, decided to build a safe passage for worshipers in order to atone for his crime.

Beginning at the age of 49, he dedicated 30 years of his life to digging the 185 metre tunnel by hand, using only a hammer and chisel.

Aonodōmon was made famous by a popular book written by author Kikuchi Kan. Media related to Aonodōmon at Wikimedia Commons