Onsen, a word that literally means "hot spring," are natural hot water baths rich in beneficial minerals. There are various types of onsen available, including popular ones like outdoor baths (roten-buro) and indoor baths (noten-buro).

A sento is a public hot bath that typically does not use naturally sourced hot water as with an onsen. In addition, there are "super sento" establishments that offer a more luxurious experience with a variety of saunas, baths, and additional services.

Onsen can be easily identified once you know what to look for. They typically have drapes (noren) at the entrance and are often marked with a symbol that resembles a steam rising from a hot spring (♨) or the character 湯/ゆ.

Sento, on the other hand, may appear similar to onsen at first glance, but they are usually found in urban areas rather than rural ones, since they are not sourced from natural hot springs.

While it is possible to find onsen in large cities, the "hot bath" symbol in an urban setting usually denotes a sento rather than an onsen.

The term "onsen" can refer to both the hot spring itself and the accompanying facilities, which are often part of a hotel, resort, or traditional Japanese inn called a "ryokan."

If you plan to visit for a day and have not made a reservation, you can typically purchase a ticket from a vending machine or from a person stationed near the entrance.

It's worth noting that some facilities require visitors to remove their street shoes at the entrance, providing lockers or shelves for storage. In other cases, you may remove your shoes just before entering the bathing area. When in doubt, observe others and ask the staff for guidance.

If you are carrying luggage, you may want to ask the staff whether they offer temporary storage at the reception desk. However, it is generally advisable to avoid bringing large bags unless you plan to stay overnight.

Make sure you bring a small towel with you but don’t worry if you can’t. Onsen usually allow you to use their clean towels - but it may be a paid service. Check at the entrance to the facility.

Finally, note that while you can take a small towel with you into the bath area, you can't enter the water with it.

It's common practice (and courteous) to wash yourself off before entering the bath, even though you may observe some people just rinsing themselves off. If you brought your own soap, be sure to leave it neatly placed by the shower to avoid inconveniencing other visitors.

Along with all the above, some unwritten rules can often evade those who don’t go to an onsen (or sento) frequently.

Kusatsu (Gunma Prefecture): This is arguably one of the most famous “onsen towns” in Japan. Not too far from Tokyo, this area is an onsen resort with tens of baths, some of which are even free (and managed by the city or the community).

Hakone (Kanagawa Prefecture): Hakone is the most famous onsen resort among those around Tokyo. You will be able to enjoy soothing baths and the boiling sulphur springs of Owakudani Valley. And don’t miss the beautiful Fuji-Hakone-Izu National Park, and one of the most iconic views of Mount Fuji as well as many shrines and a boat tour on Lake Ashi.

Kurokawa (Oita Prefecture): Kurokawa is a beautiful small town to journey on foot. With nature all around, and with beautiful wooden buildings, it transpires culture and history. Many of its baths are open-air, making it a very sought-after location for onsen. Some of its smaller ones are also the most historically important, located by the Kumamoto Castle, and dating back to the feudal era when many lords used to enjoy them.

Noboribetsu (Hokkaido Prefecture): Noboribetsu is known for its “Hell Valley” (Jigokudani), a characteristic volcano crater that gives onsen waters unique characteristics. Sitting in a setting straight from a fantasy book, demon statues decorate the city center, and rural paths take you through the Noboribetsu Primeval Forest and to amazing views of Lake Kuttara.

Experience the ultimate relaxation and rejuvenation at the best onsen resorts in Japan. Discover the unique properties of different mineral-rich waters and unwind in a variety of indoor and outdoor baths on an onsen tour!

Visitors to Japan should not miss the opportunity to visit an onsen and experience the unique and therapeutic properties of its waters. With a variety of onsen destinations throughout the country, there's something for everyone, from bustling onsen towns to tranquil, secluded locations surrounded by natural beauty.

Be sure to check out the following articles for more information on onsen in Japan!