In my research of Nagano's Top 100 Onsens, the latest one I went to is Kakeyu Onsen. I've been to Kakeyu many times, but this time I wanted to check out the main public bath, Monju no Yu.
First, a bit of background on Kakeyu Onsen. The name means 'The onsen that a deer revealed'. According to legend, a particularly religious local hunter went to the mountains to try to find some game. He wasn't having luck finding any animals, and ended up walking deeper and deeper into the mountains. As he was about to give up and return, he spotted a deer grazing. He took up his bow and shot an arrow that hit the deer in its back. The deer ran off with the arrow still attached. As fast as the hunter chased, he couldn't keep up with the deer. Since it was getting dark, he decided to return home. The next day, he searched the area where he encountered the deer but to no avail. As he was about to go back home, he saw the deer bathing in a pool of water, apparently fully healed. Just then, Monju Bosatsu (the bodishattva of wisdom) appeared. "In recognition of your fervent belief, I am revealing the location of this onsen to you. Share it with everybody."
In Kakeyu Onsen, there is a temple dedicated to Monju Bosatsu (said to be one of the top three of such temples in Japan), and the main public bath is named Monju no Yu, in honor of the diety.
Monju no Yu is the current configuration of Kakeyu's O-Yu main bath. Historically, none of the inns had their own baths. Residents and visitors alike would come to the O-Yu to bathe. Nowadays, the 22 current inns and hotels have their own onsen baths, and many residences have soaking baths and/or showers. Yet even today, it is common to get a change of scenery and try another onsen bath, hence the popularity of Monju no Yu.
Located next to the original spot where onsen water first came to the surface (some 1200 years ago), the current Monju no Yu bathing facilities were built relatively recently (1990's?). The location overlooks the Uchimura River and is adjacent to Godaikyo, Kakeyu's symbolic wooden covered bridge that leads to the Monju Bosatsu temple. It's a picture-perfect location, and so tranquil. Walking down the lane from Kakeyu's main street to the river, it's like a different world, one that time left behind and that belongs to nature with the shady wooded valley and gurgling stream below. It was easily 5 degrees cooler down by the bridge and bathhouse than up on the main street.
Also, a little more bit of background on Kakeyu Onsen. It is the home to Kakeyu Hospital which specializes in rehabilitation, taking advantage of the rejunivate power of the onsen water. In fact, a majority of the guests to Kakeyu come for extended stays (called 'Touji' in Japanese) -- to recuperate after an operation, to rest up in the farming off-season, to take time to write a book, etc. The relatively cool (38-40 deg C) temperature of the onsen water lends itself to long, leisurely soaks. And the town is fairly compact with just the degree of hills to make going for a stroll a bit of good exercise. Several of the inns offer "Ji-sui" where guests cook for themselves during their long stay.
Along with nearby Reisen-ji Onsen and Oshio Onsen, Kakeyu is a designated National Recuperative Onsen District. The mineral content of the onsen water is considered to be so good for your body when taken internally (i.e. for drinking) that Kakeyu was selected as the Ozeki (top in sumo ranks) of Eastern Japan.
With its legendary origins, history and rejuvinative waters, I wanted to give Kakeyu Onsen's Monju no Yu a try. And, so, does it make Tyler's Top 100 Onsens of Nagano list?
If one (any one at all) of the showers had more than just a trickle,
if the baths had even just a small water spout (I don't care if the baths have to be recirculated -- have some of the water enter the bath from a spout; that is one of the essential things that make an onsen an onsen!)
if the outdoor bath had more than just a peek-a-boo view of the Uchimura River and the iconic Godaikyo bridge,
then it would make my Top 100 list.
So, Kakeyu Onsen is definitely one of Nagano's more important onsen districts -- I just suggest not limiting yourself to the official public bath Monju no Yu; Try a bath in one of the hotels, too. And you can't go wrong with Saito Hotel. Their outdoor bath features an exquisite garden.