It is called 'Nageire-do Hall' and is located in a cliff on the mountain side of Mt. Mitoku around Chugoku mountain range; its name came from the story that Enno Ozunu (En no Gyoja) (a semi-legendary holy man noted for his practice of mountain asceticism during the second half of the seventh century) that was formerly regarded as an ancestor of Shugendo, made the hall by throwing building materials into the cliff from the air.
中国山地につらなる三徳山山腹の岩窟内に位置し、従前より修験道の祖とされる役小角（役の行者）が、空中から建築資材を投げ入れて造ったと伝承されてきたため、「投入堂」の呼称がある。