I've been visiting this hot spring once to three times a year for about 15 years, and it boasts one of the highest concentrations of radium in Japan.The three bathhouses, Shitanoyu, Uenoyu, and Okunoyu, are jointly managed by three inns: Kampukan, Jizaikan, and Hogando.No matter which of the three ryokan you stay at, you'll have the same bath (only Jizai-kan has its own private bath inside the hotel), so your choice of inn will depend on what you're looking for in your stay.The owners of the three inns are related, but each inn has its own unique style and attention to detail, making it interesting. Please refer to each inn's homepage and reviews for the differences.Returning to the hot springs, each of the three bathhouses has two to three bathtubs, and the main bathtub is kept at an insensible temperature. You will feel as if you are surrounded by amniotic fluid, and it will be a long bath. Some people are reading books, while others are dozing off. Although the water is fed directly from the source, it is heated by 1 to 2 degrees using a heat exchanger and a heater installed in the bathtub only during the winter. When you go up, take a bath in a bathtub heated to around 41 degrees. A very nice hot spring.The best option is Shitanoyu, but only Shitanoyu requires a long flight of stairs, which may be a hurdle for people with walking disabilities or the elderly, so it is best to choose between Uenoyu and Okunoyu. By setting the gender of the hot springs to be the same as the hot springs, even people who have difficulty climbing long stairs can enjoy the hot springs. Men's and women's hot springs change daily, so if you have particular preferences such as wanting to take a bath on your check-in day, it's a good idea to inquire in advance.At Kampukan, meals are delivered at 8 a.m. and 6 p.m. Lunch is not provided, so if you are staying for multiple nights, you will have to prepare it in advance or go to town to eat. You can choose to stay with two meals or without meals; there is no option to only have one meal.Regarding transportation, only Jizaikan has a shuttle service to and from Urasa Station on the Shinkansen, but Kampuukan and Hogando must be accessed on their own. There is a free parking lot, so it is easy to access by car. Route buses used to run fairly frequently between Koide Station on the Joetsu Line and Tochiomata Onsen, so even JR express buses (however, in the case of express buses, you need to walk about 30 minutes to the nearest route bus stop) However, access was easy, but now the bus frequency has been reduced. I hope that bus services will be restored.