Shizu-no-Iwaya is a mysterious scenic area in Onan, Shimane Prefecture, where nature and religious traditions have been closely connected for centuries. Located on the mountainside of Mount Misen near the Hiroshima Prefecture border, the area is characterized by enormous boulders and unusual rock formations scattered throughout the forest.
Shizu-no-Iwaya has long been regarded as a sacred place and was once used as a site for Shugendō mountain ascetic practices. It is also associated with Japanese mythology. According to local tradition, the deities Ōkuninushi-no-Mikoto and Sukunahikona-no-Mikoto stayed here while working on the creation and development of the land of Japan.
The area is also mentioned in the Man’yōshū, Japan’s oldest major collection of poetry, reflecting its long-standing cultural and spiritual significance.
The most striking feature of Shizu-no-Iwaya is the remarkable collection of huge rocks found throughout the mountain. Over countless years, weathering and erosion removed the surrounding soil and exposed these masses of biotite granite.
The rocks are characterized by their rounded shapes and unusual arrangements. Some appear to be delicately balanced on top of one another, creating scenes that resemble natural works of art.
Individual formations have been given names such as Tengu Rock, Tobiiwa, and Gyōba Rock. Their shapes can look completely different depending on the angle from which they are viewed, encouraging visitors to use their imagination as they explore the area.
In 1979, the rock formations were designated by Shimane Prefecture as both a Natural Monument and a Place of Scenic Beauty, recognizing their geological and scenic importance.
At the heart of the area stands Shizu-Iwaya Shrine, which has served as an important center of local worship for generations.
One of the shrine’s most sacred features is Kagami Rock, which is regarded as the shrine’s sacred object. Numerous small holes can be found across the surface of the rock. According to local tradition, passing a strip of twisted paper through one of these holes can bring good fortune or help form a meaningful relationship.
Another natural treasure is the clear spring water that emerges from between the rocks. Known as Yakushimizu, the water has traditionally been believed to have healing properties and is included among Shimane Prefecture’s selection of 100 Famous Waters.
For visitors, the spring represents a fascinating combination of nature, local tradition, and spiritual belief that has been passed down through generations.
A maintained observation trail allows visitors to explore Shizu-no-Iwaya on foot. The route begins near the shrine’s worship hall and takes approximately 20 minutes to reach the summit of Mount Misen.
Along the way, visitors encounter one impressive boulder and unusual rock formation after another. The surrounding forest contains Japanese cedar, hinoki cypress, sawtooth oak, and other trees, creating beautiful scenery throughout the year.
Fresh greenery adds color in spring, while autumn brings brilliant foliage to the mountain. Plants such as azaleas and yuzuriha can also be found along the trail, making the area appealing to visitors interested in nature observation.
From the summit, expansive views stretch across the surrounding mountains, including Mount Sanbe, as well as the rural landscape of Onan. After walking through the forest and among the giant rocks, the open view from the summit provides a refreshing sense of space.
The rocks of this area were formed by volcanic activity more than 35 million years ago. Over an immense period of time, weathering gradually transformed the original rock into the distinctive landscape seen today.
Weathering progressed along cracks inside the rock, causing the exposed masses to become rounded. The resulting formations, in which rounded blocks are stacked together, are known as core stones.
These geological features are scientifically valuable and provide an opportunity to learn how natural landscapes develop over immense spans of time. At the same time, the same rocks have been revered as sacred objects for centuries, demonstrating the deep relationship between the natural environment and local religious traditions.
Shizu-no-Iwaya does not have the atmosphere of a busy tourist attraction. Instead, its quiet surroundings and mysterious rock formations have made it a little-known destination often regarded by visitors as a spiritual place of power.
Walking slowly through the forest while listening to the sounds of birds, wind, and nature can provide a welcome opportunity to escape the pressures of everyday life.
For local residents, the area has traditionally been more than a sacred site. It was also a place where children played and where generations of people came to pray. Local residents continue to care for the area through activities such as clearing vegetation and maintaining the paths.
Shizu-no-Iwaya is approximately 20 minutes by car from the Oasa Interchange on the Hamada Expressway, or about 25 minutes from the Takada Interchange.
Because the visit includes walking along a mountain trail, comfortable clothing and sturdy walking shoes are recommended. Take your time to explore the rocks, forest, shrine, and surrounding scenery while respecting this naturally and culturally significant site.
With its ancient rocks, sacred traditions, connections to Japanese mythology, and beautiful mountain scenery, Shizu-no-Iwaya offers a distinctive opportunity to experience a quieter side of Japan. Here, geological history, nature, mythology, and faith come together in a landscape that has inspired people for countless generations.