Siebold’s Footbath
This footbath, as well as the nearby Siebold no Yu spa, is named for the German physician and botanist Philipp Franz von Siebold (1796–1866), who came to Japan in 1823. He collected and took notes on the flora, fauna, and folk culture of Japan, based on which he wrote several influential early modern works about the country.
In 1826, Siebold made the journey along the Nagasaki Highway from the port of Nagasaki to Kokura in northern Kyushu. Ureshino was a bustling spa town at the time, with more than double the number of hot-spring inns it has today. As Siebold passed through the area, it is believed that he stopped at this footbath to rest his feet in the hot water. The quality of the spring water piqued his interest, and he was one of the first to collect data on the waters of Ureshino.
Siebold’s Footbath marks the end of the Kyushu Olle Ureshino Course, offering tired travelers a chance to soothe their feet in the hot-spring water as Siebold did.
Hot Springs Straight from the Earth
The water temperature at the source of the footbath is around 100°C, but it is naturally cooled to between 80 and 90°C in the course of being pumped. The bath’s designation as gensen kakenagashi (pure, free-flowing spring water) is one highly sought after by hot-spring inns in the area, as the label allows them to promote their water as naturally sourced and pure. The water is too hot for bathing (usually 40 to 45°C) and to add cold water would dilute the hot spring water’s silken texture. Adding cold water, moreover, is considered an additive, reducing the purity of the spring water, and its use can disqualify an inn to use the gensen kakenagashi label as a promotional tool. To get around this, some local inns cool down pure the hot spring water in storage tanks, then add freshly pumped hot spring water to adjust the bathing temperature and maintain the water’s purity.