In researching Nagano Prefecture's Top 100 Onsens, one thing that I've realized is that several outstanding onsens are being left out because of the arbitrary line made up by the prefectural border. Literally just one mountain away from Nagano are such famous onsens areas such as Kusatsu and Manza in Gunma Prefecture, Oku-Hida in Gifu, Unazuki in Toyama, and Akakura in Niigata. The other day, I went for the first time to one other such neighboring onsen: Matsunoyama in Niigata.
Matsunoyama Onsen is known as one of Japan's Top 3 Medicinal Onsens, and it's mineral waters have a strong salt taste as well as a mild oilly aroma -- definitely unique enough to justify its Top 3 designation to me.
This area of the Niigata/ Nagano border is considered to be Snow Country, and it certainly lived up to its billing the day I went. Driving through thickly falling snow, we were a little nervous that there would be something worthwhile at the end of the road.
And we were not disappointed. I went with my fellow junior innkeepers from our onsen town Togura-Kamiyamada and we stayed at the inn of Yanagi-san, active on the national junior innkeepers association. His inn, Chitose, features "Tsukimi no Yu", an outdoor bath with a hefty roof over it. Practically embedded in deep snow, this one bath seems to represent the best of all of Matsunoyama Onsen.
Matsunoyama is approximately 100km from our onsen town, Togura-Kamiyamada and is approx. 2 hours and 15 minutes by car. Or by train, 25 minutes to Nagano Station and then almost 2 hours on the leisurely JR Iiyama Line to Tsunan Station.
Matsunoyama is also famous for its 'Muko-nage, Sumi-nuri' festival held annually every January 15th. Sons of neighboring towns who have taken local lasses away in marriage (= 'Muko') are thrown ("nage") off a hill, then everyone takes charcoal ("Sumi") and rubs ("nuri") it on everyone else. With a little bit of planning, this festival can be enjoyed in conjunction with Nagano's most famous winter-time festival, Nozawa Onsen's fire festival, held on the evening of January 15th.