Akasawa: the birthplace of forest bathing

By Akihiro Wada · Field notes · June 2026

I drove deep into the Kiso valley to visit the forest where shinrin-yoku started in Japan.

The birthplace, and what that actually means

Akasawa Natural Recreation Forest, in Agematsu, Nagano, is called 森林浴発祥の地 — the birthplace of forest bathing. The claim is precise, and worth getting right.

In 1982 Japan's Forestry Agency coined the word shinrin-yoku, and that autumn the first national forest bathing event was held here. The forest itself had been designated Japan's very first Natural Recreation Forest a decade earlier. The Forest Therapy Base certification system — the scientific scheme that assesses forests for measurable relaxation effects — came later, in 2006, and Akasawa is part of that too.

It is far away

Akasawa is not near anything. You travel deep into the Kiso valley, which is already remote, and then you drive another thirty minutes from there.

The Kiso cypress here are over three hundred years old. We see cedar forests of this age elsewhere, but it is unusual to see a cypress forest grown this old.

For four hundred years this forest has supplied the finest timber in Japan. Its cypress was taken for castles, and it is still the source of the goshinboku — the sacred timber used to rebuild Ise Jingu, Japan's most important shrine, every twenty years. Along the trail you pass the felling site where those sacred trees were taken.

The oldest trees are gone. They are standing in a shrine.

In the 1600s, after the Edo building boom stripped the Kiso mountains, the Owari domain forbade felling on pain of death. That is why anything survived at all. A practice we now associate with gentleness, with lying down and breathing slowly, exists because of a law that executed people for cutting wood.

Variety

Akasawa has a great diversity. This is not a monoculture plantation. Walking the Komadori course in early June, we saw many different trees and some flowers were blooming. The air is genuinely fragrant; the Environment Ministry lists this forest among Japan's hundred most fragrant landscapes.

The Komadori course is the one to walk if you only walk one. It is a little over a kilometre, it follows the stream, and it takes you past the felling site itself — the place where the sacred trees for Ise Jingu were taken. At Sawarakubo it passes the two largest trees left in the park, a giant hinoki and a giant sawara, which are worth standing under for a while in silence.

And there is a detail I only learned afterwards, which I liked enormously: the stretch of this course between Asunaro Bridge and Sawarakubo is the flattest ground in Akasawa, and it is the section where the physiological experiments for the forest therapy certification were actually carried out. The measurements that helped build the scientific case for shinrin-yoku were taken on a path I had walked without knowing it.

And then, the part we did not expect

I found a clearing, put down a mat, and lay on my back for about fifteen minutes. Fifteen. I looked up at the canopy, the light moving through it, the branches shifting. I did not meditate. I did not do anything.

Then I got up, walked out, and started the drive back.

Within twenty minutes I was yawning so hard I could not stop. Not tired — I had barely exerted myself — but so deeply relaxed that staying alert at the wheel became a genuine problem. I had to pull over for coffee in order to drive safely.

I have read the studies. I have quoted the cortisol figures on this very website. But nothing in the literature prepared me for the physical fact of a fifteen-minute lie-down in a forest producing an effect strong enough to make driving unwise.

The signs in the forest, and the room full of evidence

Along the therapy road there are interpretive boards — actual research data, staked into the ground beside the path you are walking.

One shows salivary cortisol before and after a one-kilometre walk: in the forest the line falls steeply, in the city it barely moves. Another shows the phytoncide content of the air, with α-pinene running to several thousand nanograms per cubic metre. You are, quite literally, standing inside the graph.

Inside the visitor centre there is more: a wall of question-and-answer cards, in Japanese and English, patiently explaining the science.

And then the honesty of the framing. One card asks directly: what illnesses do forest bathing and forest therapy treat? The answer is admirably plain. At present, they do not cure specific diseases. The purpose is to support everyday wellbeing and resilience, not to treat illness.

If you go

Akasawa is open roughly from late April to early November and closes for the winter, when snow reaches a metre and a half. Guided walks are available through the local NPO. Come from Nagoya or Nagano rather than Tokyo; it is not a day trip from the capital.

Akasawa Natural Recreation Forest (赤沢自然休養林) is in Agematsu Town, Nagano Prefecture. Visited June 2026, Komadori course. Historical details drawn from the Forestry Agency, Agematsu Town Tourism Association and the forest's own interpretive materials.