A depiction of the Sanzu River in Tosa Mitsunobu's Jūō-zu (十王図). The good can cross the river by a bridge while the evil are cast into the dragon-infested rapids.
The Sanzu River (Japanese: 三途の川 Sanzu-no-kawa), or River of Three Crossings, is a Japanese Buddhist tradition and religious belief similar to the Greek concept of the River Styx. It is believed that the dead must cross the river on the way to the afterlife, a belief reflected in Japanese funerals when six coins are placed in the casket with the dead.
The Sanzu River is popularly believed to be located in Mount Osore, a suitably desolate and remote part of Aomori Prefecture in northern Japan.