An explanation of the search criteria for the public bathing facilities listed on this website.
What’s It Got?
Hot Stone Spa
Called ganbanyoku (岩盤欲) in Japanese, Wikipedia tells me that this originated in Thailand, but in any case it is a popular beauty treatment service whereby users lie down on flat magma stones that are heated to 42-44°C. The heated stones apparently emit far-infrared rays which are supposed to help with metabolism and circulation, while the sweat emitted from your body has detox benefits. Although it is often termed “hot stone bathing” or “hot stone bath” in English, no water is used. Charges for this service are typically in addition to the entrance fee.
Does the onsen have a massage service? These can range from full body massages to foot massages, Thai-style, Korean-style, and so on. Again, this service will be an additional charge.
A very limited number of hot springs do have a mixed sex bathing section. All users will be required to wear swimming gear.
Near Train Station
Pretty self-explanatory. But even in the urban areas some onsen are a bus ride away from the nearest train station and not the easiest places to find without a connected smartphone. If you’re looking for convenience, check this box (defined as within a short walk from the nearest train station).
Some day onsen are open 24 hours a day (other than an hour or so in the early morning when the baths cannot be used due to cleaning). They have comfy chairs and lockers for valuables, and are one option if you’ve missed the last train home…
Does the facilities have a sauna? In Japan, the saunas at the onsen come in all types and sizes, from dry Finnish saunas to salt hearth saunas, mist saunas, and more.
See here for a more detailed article on the tattoo policy at the day onsen. In short, many deny entry to those with body markings due to its historical and cultural association with the criminal aspects of society. This option lets you filter on onsen that do allow entry to those with tattoos. At present, facilities with such lenient policies are definitely in the minority, but there are hopes that gradually rules will be relaxed.
Especially in western Tokyo you will find many onsen where the natural water is a blackish/brown, and from above a pure pitch black.
Yes, that’s right, totally free. To be honest, these free onsen are few and far between and almost always in hard to reach places, but they are always a small treasure to find.
While most onsen offer canteen-style food (Japanese curry, etc.) there are a few that have small restaurants offering excellent local cuisine for reasonable prices.
Onsen with a View
What could be better than soaking while in hot spring water while gazing out onto forest, a Japanese stone garden, or even Mount Fuji!
This one is for onsen that offer a full suite of additional pampering services like hot stones spas and full body massages services…
Zen Level Peaceful
Of course bathing at the onsen is a relaxing experience, but there are some bathing houses that just take it to the next level…