Unzen has been popular among foreigners as a summer retreat for over a century

Unzen hot springs became known as a summer retreat among foreign tourists in 1889, when the North China Daily News, issued in Shanghai, published an introductory article on Unzen hot springs. Since then, the number of foreign families who spend the summer at Unzen as a summer retreat have increased. As Unzen hot springs became more famous overseas, for westerners stationed in Shanghai, it became the resort and summer retreat destination of choice.
Afterward, as the Shanghai-Nagasaki sea route was opened, the number of visiting foreign tourists increased, and over the summer, visitors stayed from between 2 weeks to a month at Unzen.
During their stay, they hiked the mountains of Unzen, enjoyed ballroom dancing, and at night, rinsed off in the hot springs. Furthermore, in 1913, golf courses and tennis courts were developed, providing even more options for entertainment.