A traditional outdoor onsen bath surrounded by autumn leaves

Onsen: The Complete Guide to Japan's Hot Spring Culture

What is Onsen? Onsen (ๆธฉๆณ‰, literally โ€œhot springโ€) refers to naturally occurring geothermal water heated by volcanic activity underground. Japan sits on the Pacific Ring of Fire and has over 3,000 onsen towns across the country, making it the worldโ€™s preeminent hot spring culture. But onsen is far more than just a bath. Itโ€™s a cultural ritual, a social institution, and for many Japanese people, an essential part of life. Bathing in natural mineral waters together โ€” in its traditional form, without swimwear โ€” represents a moment of pure equality and communal relaxation that has no real equivalent in Western culture. ...

May 18, 2026 ยท 6 min ยท Japan Insider Team