Types of hot springs
There are many types of hot springs to enjoy. The conventional hot spring is a hot water bath. Depending on the spring, different minerals are dissolved in the water, giving it different health benefits, colors and smells. Many hot springs contain sulfur and have an according odor.
Hot spring water baths come indoors, outdoors and in many different sizes. Outdoor baths are called rotemburo. While some baths are wooden or stone tubs, others are built to resemble or are actually natural hot spring pools. Some outdoor baths are spectacularly situated in the mountains, valleys or along rivers, lake or sea shores.
Besides conventional hot water tubs, a popular feature of larger baths are so called waterfalls, which comfortably massage your shoulders if you sit below them. Other bath types include sand baths, where bathers are buried in naturally heated sand, mud baths and steam rooms.
Ashiyu are shallow hot spring pools for bathing just your feet. They are found in the streets of many hot spring resorts and can be used free of charge.
Increasing in number are modern hot spring complexes, which offer a range of baths, massage services, saunas and sometimes conventional swimming pools, water slides, etc. In Tokyo, where there is a shortage of natural hot spring water on the surface, some new hot spring complexes are retrieving their water from a depth of more than a kilometer below sea surface.
The ultimate hot spring experience is spending a night at an onsen ryokan, a Japanese style inn with hot spring baths. This is not only one of the most popular holiday activities among the Japanese, but is also highly recommended to any foreign visitor of Japan.
Onsen ryokan are found in various sizes in hot spring resorts across Japan. A typical onsen ryokan visit starts with a bath before dinner. The beautifully arranged Japanese style dinner, featuring local specialties, is either served in your tatami room or in a dining hall. Many guests like to take another bath before sleeping and before breakfast in the next morning.
You do not need to stay overnight at a ryokan in order to enjoy its baths. Many ryokan open their baths to the general public, typically during daytime only and against an admission fee of a few hundred yen. Besides ryokan, most hot spring resorts also have some public bath houses with hot spring water.
Hot springs in Japan are enjoyed naked, even though there are a few exceptions. While a majority of baths are gender separated, some are mixed. Mixed baths are usually found in more remote areas.
Furthermore, some establishments have both, gender separated and mixed sections, for example, in the case that there is just one spectacular outdoor bath, which the owner wants to make accessible to both genders.
For obvious reasons, many Japanese women, especially younger ones, avoid mixed hot springs, and it is not unusual that mixed pools are almost exclusively used by men.
If you do not feel comfortable naked in front of other people, you should inquire about "kashikiri" (private) baths, which are available at some ryokan. Private baths are sometimes also known as "kazokuburo", lit. family baths.