A Japanese onsen is a natural hot spring that is often used for bathing. These springs are heated by geothermal activity and are rich in minerals, which are believed to have health benefits. Onsens can be found throughout Japan, in both indoor and outdoor settings, and are popular for relaxation and wellness. Visitors to an onsen typically follow specific etiquette, such as washing thoroughly before entering the communal baths. Onsens can vary in style, from traditional ryokan inns to modern facilities, and many offer beautiful views of nature, enhancing the overall experience of soaking in the warm waters.