Yusan no Ri Onsen / Photo by MOKUTANG

This is a place I visited a couple of years back, during my run at the "Beppu onsen master" challenge. Beppu has truly countless springs — from flashy large resorts to traditional ryokans, the options are endless. But one place has stayed with me more than most: Yuyama no Sato Onsen.

This place is about as far from a typical, clean onsen facility as you can get. Deep inside a massive bamboo forest, a small onsen sits on private land, said to be built and maintained entirely by hand, by an elderly couple. Literally a wild onsen, made by human hands and nature together.

(Looking at recent Google reviews, a roof has since been added above the bath, so it looks a little more maintained than when I visited. Still, the rough, unpolished atmosphere the place is known for seems to remain.)

One other feature here: it's mixed bathing. The front desk seemed to sell disposable swimsuits, but reviews mentioned the material was a thin, non-woven fabric... so just in case, I brought my own swimsuit. Preparedness matters.

When we arrived, quite naturally, a fully nude Japanese man was alone, enjoying this small paradise entirely to himself. The moment he spotted us, though — a flash of "oh no" across his face, and he grabbed his clothes and hurried off. I felt a little bad for interrupting his peaceful soak.

A walk through bamboo just to reach the water

Yusan no Ri Onsen Bamboo Forest Path / Photo by MOKUTANG

This isn't a comfortable place for everyone. You have to walk a path through the bamboo just to reach the tub itself — it was a fairly long walk, from what I remember — and the changing space is genuinely modest. Don't expect a shower, either.

But maybe enduring exactly this kind of inconvenience to find a place like this is the actual appeal of a hitou — a hidden, secret onsen.

The water color alone tells you it's a simple sulfur spring

As the water's color makes clear, this is a simple sulfur spring. From a distance, you already catch a faint — no, honestly, quite strong — rotten-egg smell drifting toward you. That smell is how you know: ah, almost at the onsen.

Yuyama no Sato Onsen / Photo by MOKUTANG

Honestly, the water itself wasn't hugely shocking — Japan has plenty of sulfur springs at this same quality. What made this place special wasn't really the water. It was the atmosphere built by the person, and the space, that made this onsen exist at all. Deep in a bamboo forest, a small hand-made open-air tub, and time spent genuinely inside nature. That was this place's real value.

After properly enjoying Yuyama no Sato Onsen, we moved to the nearby Yuae-bisu and immediately hit a second bath. In Beppu, once you've visited one good onsen, another one always starts pulling at your curiosity. Every single soak makes you understand, a little more, why Beppu is called the "city of hot springs." Maybe that's exactly why anyone who's been there once always ends up going back.

Yuyama no Sato Onsen 874-0004 Noda, Beppu, Oita, Japan