The mountain that gave alum
The name Myoban means alum, the crystal once used in dyeing and to stop bleeding, which was harvested here in the Edo period. In 1725 Watanabe Goroemon perfected a way of growing crystals from steam and clay, and under the Mori domain it became an industry. When demand for alum disappeared, the same technique went on producing yunohana, now sold as bath salts.[2][3]
Crystals growing inside a hut
The huts are thatched with straw and floored with blue clay. As volcanic steam rises through the clay its minerals crystallise, growing about a millimetre a day; after 40 to 60 days the crystals are harvested and dried. On 15 March 2006 the technique was designated an Important Intangible Folk Cultural Property. The huts can be viewed free of charge.[2][4]
When a spring fades
Kakujusen, the municipal bath in Myoban, was free, its 'fee' a coin to the stone Jizo by the door. But the spring's flow declined, and it has been closed since 16 March 2020. Springs wax and wane; Beppu has more than 2,000 of them, yet each bathhouse depends on its own.[6][7]
