What are Onsen?

Onsen, or hot springs, first became popular in Japan over a thousand years ago. Originally limited to the aristocracy, their usage soon spread to include the military, whose battle wounds could benefit from the healing properties of the water. Today, everyone in Japan can enjoy onsen, as they are located by the hundreds in every region across the nation. Their water comes from underground springs, usually as a byproduct of Volcanism, and contains many minerals which are said to soothe, relax, and heal the body. If you are taking a trip to Japan, you should definitely plan to include a visit to an onsen in your stay.

Types of Onsen

There are many different types of onsen available for your enjoyment once you choose to visit Japan. Some are mixed gender, though most are gender specific. Some are located indoors, while others are found outside. Some belong to a ryokan, or Japanese inn, and some are a part of public bath houses. Onsen can also be classified according to the type of minerals or healing properties they contain:

1. Simple Springs have the smallest mineral content, but are still good for blood circulation and long-term rehabilitation.
2. Carbonate Springs are good for blood circulation and neurological disorders.
3. Sodium Chloride Springs, or Salt Springs, are good for joint inflammation.
4. Iron Springs are also good for inflammation of the joints, as well as for menopausal discomforts, and chronic skin diseases.
5. Acidic Springs are hard to bathe in due to the irritation they can cause to the skin. However, the acid has, at the same time, also been known to help the skin of people with chronic skin diseases. Acidic Springs are also good for diabetes.
6. Radium Springs are good for digestive disorders and for lowering high blood pressure.
7. Sulfur Springs smell like rotten eggs but are said to be good for the arteries, as well as for many other disorders.

*These are just some of the types of minerals that can be found in onsen. There are other types of hot springs not included in this list.*

Onsen Etiquette

If you are enjoying a Japanese hot spring for the first time, there are a few things you should know before getting into the water:

1. Onsen are enjoyed naked. The first rule of onsen etiquette is that swimsuits are not allowed, so feel free to let it all air out. If the thought of being naked worries you, however, you may be able to use a small washcloth to cover up your privates as you walk around, but it must be removed before entering the onsen.
2. After you remove all your clothes, leave them behind in a basket or locker in the changing room. You’re still not ready to enter the hot springs, however. Before leaving the changing room and entering the onsen, it is first important that you wash your body. There will be an area, normally containing a stool and shower head, where you can sit and scrub yourself clean.
3. When you are finished soaking in the onsen, do not shower before redressing. It takes several hours for the minerals to be absorbed into the skin, so obtaining the full healing benefits of the hot springs requires letting the water stay on your skin.

Japan's Hidden Hot Springs

The Japanese Spa: A Guide To Japan's Finest Ryokan And Onsen