Visited in: June 2022 (Clear skies and sunshine)
Nestled in the snowy region of Tokamachi, Niigata, Matsunoyama Onsen is one of Japan’s three greatest medicinal hot springs—alongside Arima and Kusatsu.
Its naturally salty, steaming hot spring water is rich in metaboric acid, said to aid skin healing and sterilization.
With a source temperature of 97.5°C, it’s no exaggeration to say the waters here are seriously powerful! 
Built in 1938: Ryounkaku, a Registered Cultural Property
I stayed at Ryounkaku, a beautiful wooden inn built in 1938 and designated a Registered Tangible Cultural Property.
Located slightly away from the main onsen town, it's about a 15-minute stroll through quiet countryside.
Step inside, and you’re greeted by scenes from the Showa era—glass cupboards with teacups, tatami floors, soft yukata neatly folded.
It felt like time had stopped.
While the building shows signs of age, that’s exactly what gives it its incredible charm.
Guest rooms are in the main building, while the bathhouse and dining area are in a separate wing. Every creaky wooden step adds to the atmosphere, like walking through a film set 
Two Types of Onsen: 100% Natural and Flowing
Ryounkaku owns its own hot spring source called Kagami-no-Yu ("Mirror Bath") used in the main bath.
There’s also a private bath sourced from a separate spring called Taka-no-Yu ("Hawk Bath").
The private bath is first-come-first-serve—no reservation needed, just lock the door.
The water is hot, so adjust it with cold water as needed. Open the window, and you'll feel the cool breeze and see vibrant greenery outside. It almost feels like an open-air bath!
Check out the mineral analysis too—packed with sodium and metaboric acid.
Even seasoned onsen fans will be impressed by this mineral-rich water.
Sunset Stillness at a Countryside Hideaway
Surrounded by rice fields, Ryounkaku offers a peaceful escape from the bustle of the town.
In the evening, the warm glow of sunlight through the hallway windows created a nostalgic and soothing atmosphere.
Japanese Breakfast and a Bird-Shaped Sweet to Melt Your Heart
The traditional breakfast was gentle and nourishing, but what really stole the show was the adorable bird-shaped sweet!
Cute and delicious—a perfect match for a retro stay like this.
Local Delight: “Shinko Mochi” from Juichiya
Before heading home, I stopped by Juichiya, a beloved shop in the area, to pick up their famous “Shinko Mochi.”
Made with local Koshihikari rice and wrapped in leaf-like packaging, these sweet rice cakes go perfectly with a glass of sake in your room 
Far from the noise of the city, Ryounkaku offers the luxury of doing absolutely nothing—and finding joy in that stillness.
If you're looking for a retro retreat with healing waters and old-school charm, this inn is the perfect escape.