A Mysterious Gorge Born from Mount Otō
Mount Otō and the Source of the River
Mount Otō stands at an elevation of approximately 1,122 meters on the border between Tanabe City and Kozagawa Town in Wakayama Prefecture.
The mountain is an important source of water for several river systems, including the Kumano River, Koza River, and Hikigawa River. The abundant rainfall of the Kii Peninsula is absorbed by the forests surrounding the mountain before emerging as clear mountain streams.
This rich water environment supports the forests and ecosystems of the region and ultimately creates the beautiful river landscapes found throughout Otō Gorge.
A Rare Forest Ecosystem
The mountains around Mount Otō are home to extensive beech forests, considered among the southernmost beech forests on Honshu, Japan’s largest island.
Because the area lies at a natural boundary between warmer and cooler environments, plant species associated with both climates can be found together. This creates a distinctive ecosystem with a remarkable diversity of plants and wildlife.
The combination of abundant rainfall, pristine forests, and mountain streams is one of the reasons the region is often described as a treasure house of nature.
An Eight-Kilometer Panorama of Untouched Nature
Rushing Water, Deep Pools, and Dramatic Cliffs
Otō Gorge extends for approximately 8 kilometers through the upper reaches of the Otō River, near the area around Kawayu Onsen.
Steep mountains rise on both sides of the river, while the water cuts through the landscape, creating powerful rapids, deep pools, and unusual rock formations. The combination of towering cliffs and clear mountain water creates a dramatic wilderness landscape.
Katamanbo and Its Impressive Rock Formations
One of the most striking areas is around Katamanbo, where steep rock walls rise dramatically above the river.
The combination of sheer cliffs, enormous rocks, and deep flowing water creates an impressive scene that is difficult to fully appreciate through photographs alone.
In spring, fresh green foliage covers the mountains. Summer brings refreshing streams and opportunities for fishing and enjoying the water. In autumn, the surrounding mountains turn shades of red, orange, and yellow, transforming the gorge into a beautiful world of autumn colors.
The Kobo Cedar Legend
A Story Associated with Kobo Daishi
Otō Gorge is also connected with a local legend concerning Kobo Daishi, also known as Kukai, the Buddhist monk who founded Koyasan and established Shingon Buddhism in Japan.
According to the story, Kukai was traveling through the Kumano region on a pilgrimage. When he stopped near the foot of Mount Otō to eat, he broke off a branch from a tree and used it as a pair of chopsticks.
After his meal, he planted the branch in the ground. The branch is said to have eventually grown into two enormous Japanese cedar trees.
These trees became known as the “Kobo Cedars”. Standing quietly in the mountain landscape, they have an almost mystical atmosphere and provide a connection between the natural environment and the religious traditions of Kumano.
Otōzan Prefectural Nature Park
A Protected Landscape of Forests and Clear Rivers
The wider area surrounding Otō Gorge is protected as part of the Otōzan Prefectural Nature Park, preserving the region’s rich natural environment.
Several clear rivers flow through the mountains, including the Mae-no-kawa, Yasukawa, Otō River, Koza River, and Hirai River. As they pass through the rugged terrain, they form waterfalls, pools, and beautiful gorges.
The upper reaches of the Koza River are particularly known for waterfalls such as Ueuo-no-taki and Hario-no-taki. Their clear water and surrounding forests create peaceful landscapes where visitors can escape from the noise of urban life.
Yasukawa Gorge and Its Emerald-Green Water
A Beautiful Scenic Area Near Otō
One of the most impressive scenic areas in the Otō region is Yasukawa Gorge.
The gorge features rocks polished smooth by the mountain stream, exceptionally clear water, and dense natural forests. When sunlight reflects from the surface of the stream, the water can appear emerald green, creating an unforgettable contrast with the surrounding forest.
The area is sometimes described as one of the landscapes that represents “Water Country Wakayama,” a nickname reflecting the prefecture’s abundant rivers, waterfalls, and clear mountain streams.
A walking course around the gorge takes approximately 90 minutes, making it a relatively accessible way to experience the natural beauty of the Kii Mountains.
A Mountain Journey into a Unique Ecosystem
The Otō area is surrounded by mountains ranging from approximately 800 to 1,000 meters in elevation, including Mount Otō and Mount Hōshi.
The rugged terrain has helped preserve extensive forests that provide habitats for a wide variety of plants, birds, insects, and other wildlife. Exploring the area on foot offers opportunities to observe the distinctive ecosystems of the Kii Mountain Range.
Hiking Mount Hōshi
Mount Hōshi reaches an elevation of approximately 1,120 meters and is one of the highest peaks in the Otō mountain area.
A suspension bridge near the trailhead crosses a clear mountain stream. After passing through areas of planted cedar and cypress, the trail gradually becomes more rugged, with narrow ridges and rocky sections.
As the trail climbs higher, hikers encounter a wide variety of plants and increasingly impressive views of the surrounding mountains.
A Panoramic Mountain View
At the summit, hikers can enjoy a 360-degree panorama of the Kii Mountains. On exceptionally clear days, distant peaks such as Mount Hakkyo-ga-take in Nara Prefecture and Mount Tsurugi in Tokushima Prefecture may be visible.
The experience is not only about the scenery. The sounds of birds, flowing water, and wind moving through the forest create a peaceful environment that allows hikers to experience the mountains with all their senses.
Camping and Outdoor Adventures
The Otō area also offers several facilities where visitors can stay close to nature. These are ideal for travelers who want to spend more than a few hours exploring the mountains and rivers.
Otō Youth Travel Village
Otō Youth Travel Village is a nature-oriented campground surrounded by the Hikigawa River. It provides facilities such as cabins and elevated camping areas.
Because the area is far from major urban centers, visitors can enjoy a remarkably clear night sky filled with stars when weather conditions are favorable.
Hyakkenzan Gorge Camp Village
Hyakkenzan Gorge Camp Village is located near the entrance to Hyakkenzan Gorge and serves as a convenient base for hiking and exploring the surrounding forests and streams.
Staying here allows visitors to experience the natural environment more closely and enjoy the peaceful atmosphere of the Kii Mountains.
Roadside Station Furusato Center Otō
Roadside Station Furusato Center Otō is a convenient stop surrounded by greenery and clear mountain streams. Visitors can purchase local specialties and products from the surrounding mountain region.
It also makes a useful rest stop when traveling through the Otō area by car.
How to Reach Otō Gorge
Otō Gorge can be reached by car in approximately 25 minutes from Kumano Hongu Taisha Grand Shrine.
The gorge can be combined with visits to Kawayu Onsen, the Kumano Kodo pilgrimage routes, and other attractions in the Kumano region. Combining these destinations makes it possible to experience the area’s forests, rivers, hot springs, religious heritage, and traditional culture in a single journey.
A Peaceful Escape into the Wilderness of Kumano
Otō Gorge is a special destination where visitors can experience the vast natural environment of the Kii Mountains.
Steep mountains, crystal-clear streams, dramatic rock formations, deep forests, and seasonal scenery come together to create a landscape that feels far removed from modern city life.
The region also preserves stories connected with Kobo Daishi and the spiritual traditions of Kumano. This combination of nature and spirituality is one of the defining characteristics of the Kumano region.
By visiting Otō Gorge together with the Kumano Kodo and nearby hot spring destinations, travelers can gain a deeper appreciation of the region’s traditional concept of healing and renewal.
For those seeking a quiet encounter with Japan’s mountains and forests, Otō Gorge offers an opportunity to slow down, listen to the sounds of nature, and experience the peaceful beauty of the Kumano wilderness.