The Jigokudani Yaen-koen is located in the Valley of Yokoyu River which takes its water from Shiga-Kogen of the Jyoshinetsu-Kogen National Park in the northern part of Nagano prefecture. Looking at the very steep cliffs and the fountains of hot water, people started to call the valley ‘Jigokudani (Hell valley)’. The altitude is 850 meters, winter seasons in Jigokudani is so harsh, for example, temperatures drops to 10 degrees below zero and snow falls over 1 meter. These severities compare favorably with those of Shimokita peninsula (Aomori pref.), which is the northernmost habitat of primates except humans.

Since the establishment in 1964, the Jigokudani Yaen-koen has been popularly known as the place where we can see the wild monkeys’ biology up close. Many thousands of people from all over the world have visited here to see monkeys, especially researchers and photographers. They made a lot of accomplishments in their research and photographing.

In 1970, a photograph of bathing monkeys was appeared on the front page of LIFE and was reported by the world media. And during the period of Nagano Olympics (1998), many people from the games visited here, such as athletes, Olympic officials and news media. We captured public attention with these topics.

The Japanese macaques, well known as snow monkey (hereinafter called ‘monkeys’), inhabit all part of Japan except Hokkaido and Okinawa.

What should we do when we want to see the monkeys?
Do you go to a zoo? Yes, you can see monkeys in a zoo, but it is impossible to see their pristine actions such as high level sociality in a troop with the monkeys in a small zoo cage.
Then, do you go to mountains? Actually it is difficult to find monkeys in mountains because of deep forests and steep cliffs. Even if you luckily find them, they keep enough distance from you and run away quickly.

The best way to watch wild monkeys is to visit the Jigokudani Yaen-koen. Our objective is to provide a place where everybody can watch closely monkeys’ biology in a natural environment.
There are no fences between monkeys and us. We can enter and see their world under natural condition.

To keep monkeys’ habitat naturally, our facility is far from town.

Even though we feed monkeys, they are still wild animal. Our facility has no fences so that monkeys can come and go freely. They come to here during daytime just for seeking foods provided by us and this is only a part of their daily life. They also have their own life outside of the Yaen-koen. Their territories are in mountains around the Yaen-koen and are approximately several kilometers in radius. As we said monkeys inhabit in Jigokudani are wild animal, sometimes they stay in the mountains all day long, not necessarily come to the Yaen-koen.

Though monkeys in Jigokudani are well known as bathing monkeys, bathing is a measure to protect them against the extreme cold during winter seasons. Therefore they reluctant to take a bath during other warm seasons. Bathing is a small portion of their life.

There is a lot of interesting biology of monkeys more than bathing, why don’t you try to find it? Each season has unique ways to have fun with monkeys’ observation.

The nature of Jigokudani contributes to the life of monkeys as well as other animals, insects and plants. All lives here, including our facility, are intricately related to each other and make a harmony for their habitat.

We, the Jigokudani Yaen-koen think that we should be a placemaking of comprehensive nature observation here. You will enjoy beautiful nature of this area not only inside of the Yaen-koen but also on the nature trail and in the scenic views seen from the village at the foot of the mountain.