Located on the so-called Ring of Fire in the Pacific Ocean, Japan is one of the most volcanically active countries in the world. As a result, it has over 500 natural hot springs, or onsen. Many of these have traditionally been used as public bathing areas, and are central to the country’s culture and tourism. These geothermal hot springs are often located in stunning outdoor settings, and are said to rejuvenate the body.

Onsen should not be confused with sento. Sento are public bath houses that use mains water, which does not have the same natural mineral content. Each onsen will have a slightly different composition. The healing properties said to be in the water will depend on the minerals that are present. Most onsen can provide you with specific information about their own water.

A few different onsen varieties include Iron Springs, which have reddish water and are reportedly excellent for skin conditions, Carbonated Springs, which assist with circulation, and Sulfur Springs, which smell quite unpleasant but are said to prevent hardening of the arteries. For those who like something a bit zany, the Yunessun Spa Resort in Hakone has also added several “amusement spas” to their main facility: there is a Sake Spa, a Green Tea Spa, a Coffee Spa and a Red Wine Spa. Each is filled with the real beverage, and claim to have restorative properties!

Japan’s mountainous Hachimantai region, located in the northern Iwate and Akita prefectures, has some wonderful onsen.  As it is a volcanic region far from Japan’s cities, Hachimantai also boasts brisk, clean air and fantastic hiking trails.

Owakudani Onsen in Hakone

One popular onsen in this location is the cheekily titled “Nyuto Onsen” (nyuto means “nipple” in Japanese). It was named after the shape of the nearby Mount Nyuto. The Nyuto Onsen actually has many hot baths, belonging to eight local ryokan, or traditional Japanese bed-and-breakfast inns. All of the Nyuto baths are also open to day trippers, depending on the time of day. Some of them allow men and women to bathe together, while others are segregated. Amazingly, the Tsurunoyu Ryokan in Nyuto Onsen dates right back to the 17th century Edo Period.

If you are visiting an onsen for the first time, don’t be intimidated! Here are some tips to help you fit in perfectly:

1) Some onsen allow bathing suits, but many require you to remove your clothes. Many onsen have private bathing areas for hire, if you are shy about this. Although people will not stare at you in the public areas, you should use your towel to cover yourself when walking to the water.

2) Make sure you wash your body thoroughly before entering the onsen. The hot spring water is only for soaking. Some onsen require you to bring your own soap, but the high-end ones will include toiletries in the entry fee.  

3) Please be aware that many onsen have an issue with tattoos. However, they are usually fairly accepting of foreigners who have them, so the best advice is just to check with them beforehand.

4) Do not re-enter the changing area before toweling off.

5) If in doubt about what to do, just ask a staff member.