Furubochu Plain
Shugendo mountain asceticism is one of Japan’s oldest religious traditions. The volcanic Mt. Aso has been worshipped since ancient times, and ascetic practice was centered at Furubochu, a stretch of plains west of Mt. Nakadake.
Aso’s eruptions were once considered important omens. When an eruption occurred, believers went to Furubochu to recite fervent prayers. The Onda Matsuri, a festival at which offerings are presented to the deities of the mountain, has its origins in this custom and still takes place today.
Over the centuries, 88 Buddhist retreats known as bo and an were established in Furubochu, the first of them in the Kamakura period (1185–1333). There, ascetics recited sutras, practiced austerities and rituals punctuated by the sounding of conch shells.
Furubochu’s 88 retreats survived until the Muromachi period (1336–1573), when they suffered damage during battles between two rival Kyushu families, the Otomo and the Shimazu. The retreats were eventually relocated down the mountain to Fumotobochu, the current site of Saigandenji Temple.