Onsen

In Japan,onsen(温泉)arehot springsand the bathing facilities andtraditional innsaround them. There are approximately 25,000 hot spring sources throughout Japan, and approximately 3,000onsenestablishments use naturally hot water from thesegeothermallyheated springs.
Onsenmay be either outdoor baths(露天風呂 or 野天風呂,roten-buro / noten-buro)or indoor baths(内湯,uchiyu). Traditionally,onsenwere located outdoors, although many inns have now built indoor bathing facilities as well. Nowadays, as most households have their baths, the number of traditional public baths has decreased,but the number and popularity of hot spring resort towns (温泉街,onsen-gai) have increased since the end ofSecond World War.Baths may be either publicly run by a municipality or privately, often connecting to a lodging establishment such as a hotel,ryokan, orminshuku.
The presence of anonsenis often indicated on signs and maps by the symbol ♨, thekanji湯(yu, meaning "hot water"), or the simpler phonetichiraganacharacter ゆ (yu).
According to the Japanese Hot Springs Act(温泉法,Onsen Hō),onsenis defined as "hot water, mineral water, andwater vaporor other gas (excludingnatural gasof which the principal component ishydrocarbon) gushing from underground".The law states that mineralized hot spring water that feeds anonsenmust be at least 25 °C (77 °F) originating at a depth of at least 1.5 kilometres (0.93 mi), and contain specified amounts of minerals such as sulphur, sodium, iron, or magnesium.
Whenonsenwater contains distinctive minerals or chemicals, establishments often display what type of water it is,in part because the specific minerals found in the water have been thought to provide health benefits.Types include sulfuronsen(硫黄泉,iō-sen), sodium chlorideonsen(ナトリウム泉,natoriumu-sen), hydrogen carbonateonsen(炭酸泉,tansan-sen), and irononsen(鉄泉,tetsu-sen).
Exactly when humans first began bathing inonsenin Japan is unknown, but historical records show it has a history of at least about 1,300 years.Many of the earliest records ofonsenbathing documentJapanese Emperorsor members of theimperial familystaying atonsenfor long periods of time. At the time,onsenwere thought to be sacred and to have healing properties.It is now believed those who traveled toonsenin these early records were seeking cures to disease or other ailments by bathing in theonsenwater.This ancient practice of bathing inonsento cure illnesses, often for long periods such as a week, is referred to astōji(湯治).Some of the oldestonsenin Japan are considered to beDogo OnseninEhime Prefecture,Shirahama OnseninWakayama Prefecture, andArima OnseninHyogo Prefecture.
Until around theEdo period,onsenhad close religious ties toBuddhismwithtemplesoften being built nearonsensources.During the Edo period, however,onsenbegan to gain popularity among the general population thanks in part to depictions of the hot springs inukiyo-e.It is also during this period that the use ofonsenshifted from being primarily for religious and healing reasons to being used for bathing for cleanliness and socializing.
In modern times, traveling to hot spring resort towns (温泉街,onsen-gai) is a popular form ofdomestic tourismin Japan.During thebubble economyof the 1980s, there was a "onsenboom."Although the number of overnight guests at hot spring resorts has decreased slightly since the boom, travel to suchonsentowns as a relaxing getaway is still popular among Japanese people.
Traditionally, men and women bathed together at bothonsenandsentōcommunal bathhouses, but gender separation has been enforced at most institutions since the opening of Japan to the West during theMeiji Restoration.
Mixed bathing(混浴,kon'yoku)is currently banned in Japanese public baths.Depending on theprefectureand local ordinances, children seven years old and younger may be exempt from this ban.
Privateonsencalled "family baths" (家族風呂,kazokuburo) can be found in many locations throughout Japan. These can be reserved and used for mixed bathing.
As at asentōat anonsen, all guests are expected to wash and rinse themselves thoroughly before entering the hot water. Bathing stations are equipped with stools, faucets, wooden buckets, and toiletries such as soap and shampoo; nearly all onsen also provide removable shower heads for bathing convenience. Entering theonsenwhile still dirty or with traces of soap on the body is socially unacceptable.
Guests are not allowed to wearswimsuitsin the baths and must be completely nude. However, there are someonsenthat allow both men and women to enter together but require swimsuits. Many of these mixedonsenresemble more of apoolorwaterparkthan the traditional idea of anonsen.In 2016, The Japan Times reported that guests were not normally allowed to wear swimsuits in the baths. However, some modernonsenrequired their guests to wear a swimming suit in their mixed baths.
Onsenguests generally bring a small towel with them to use as a wash cloth. The towel can also provide a modicum ofmodestywhen walking between the washing area and the baths. Someonsenallow one to wear the towel into the baths, while others have posted signs prohibiting this, saying that it makes it harder to clean the bath. It is against the rules to immerse or dip towels in theonsenbath water, since this can be considered unclean. People normally set their towels off to the side of the water when enjoying the baths, or place their folded towels on top of their heads.
By 2015, around half (56%) ofonsenoperators had banned bathers withtattoosfrom using their facilities.The original reason for the tattoo ban was to keep outyakuzaand members of other crime gangs who traditionally have elaborate full-body decoration.
However, tattoo-friendlyonsendo exist.A 2015 study by the Japan National Tourism Organisation found that more than 30% ofonsenoperators at hotels and inns across the country will not turn someone with a tattoo away; another 13% said they would grant access to a tattooed guest under certain conditions, such as having the tattoo covered up.Some towns have many tattoo-friendlyonsenthat do not require guests to cover them up. Two such towns areKinosaki Onsenin Hyōgo andBeppu Onsenin Ōita.
With the increase in foreign customers due to growing tourism, someonsenthat previously banned tattoos are loosening their rules to allow guests with small tattoos to enter, provided they cover their tattoos with a patch or sticking plaster.
There are various health benefits attributed to bathing inonsen.Onsenare particularly renowned for their relaxing andtherapeutic effects.These effects are due to properties such as the temperature, pressure, and mineral composition of the water.
A 2014 study conducted inBeppu, a city famous for itsonsen, found that regular bathing inonsenhas various health benefits such as loweringblood pressure, improvingcirculationand cardiovascular health, reducing chronic pain and fatigue, and lowering the rate ofdepression.A survey conducted inAtami, another city famous for itsonsen, found that individuals withonsenin their homes were less likely to take blood pressure medication than those withoutonsen.
There are various types ofonsenincludingcarbonatedsprings,iron-containing springs,acidicsprings, strong-smellingsulfursprings, among others.Each type ofonsenis believed to have unique benefits. Carbonated springs, for example, are believed to lead to smooth skin.Onsenfacilities often advertise various health and beauty benefits they claim their water to provide.
Water at someonsenfacilities is drinkable.Onsenwater should only be consumed if it is confirmed to be safe to drink by the prefecture.The water should be obtained from a designated drinking source that is separate from the water which is bathed in.The often mineral-richonsenwater is believed to have benefits such as treatingiron-deficiency anemiaorconstipation.
Article 18, paragraph 1 of the Japanese Hot Springs Act publishes guidance on contraindications and cautions for bathing in hot springs, and drinking their respective waters.Although millions of Japanese bathe inonsenevery year with few noticeable side effects, there are still potential side effects toonsenusage, such as aggravating high blood pressure or heart disease.
Legionellabacteria have been found in someonsenwith poor sanitation.For example, 295 people were infected with Legionella and seven died at anonseninMiyazaki Prefecturein 2002.Revelations of poor sanitary practices at someonsenhave led to improved regulation by hot-spring communities to maintain their reputation.
There have been reports ofinfectious diseasefound in hot bodies of water worldwide, such as variousNaegleriaspecies.While studies have found the presence ofNaegleriain hot spring waters,Naegleria fowleri, responsible for numerous fatal cases ofprimary amoebic meningoencephalitisaround the world, has not been found to be present in the water atonsen.Nevertheless, fewer than five cases have been seen historically in Japan, although not conclusively linked toonsenexposure.
Manyonsendisplay notices reminding anyone with open cuts, sores, or lesions not to bathe. Additionally, in recent years onsen have been increasingly addingchlorineto their waters to prevent infection, although manyonsenpurists seek natural, unchlorinatedonsenthat do not recycle their water but instead clean the baths daily.These precautions as well as properonsenusage (i.e. not placing the head underwater, washing thoroughly before entering the bath) greatly reduce any overall risk to bathers.
Voyeurismis reported at someonsen. In 2016,The Japan Timesreported that this was mitigated in someprefectures of Japanwhere nude mixed bathing is not permitted, and that visitors must wearswimsuits.In 2021, several people were arrested in connection with an organized group accused of taking photos of women in open-air baths.
In addition to typicallarge public baths(大浴場,daiyokujō) andoutdoor baths(露天風呂,roten-buro), there are various other methods of experiencingonsenthat can be found at various facilities throughout Japan. Examples include:
Saunasare also sometimes located atonsenbathing facilities. A relatively cold bath calledmizu-buro(水風呂) is often located directly outside a facility's sauna to allow users to quickly cool down. The cycle of entering hot baths, saunas, and cold baths at anonsenfacility is sometimes referred to astotonou(ととのう) and is believed to be refreshing and to have health benefits.