
Guida
Kozonsokei Valley is a breathtaking scenic spot located in the remote western part of Shimanto City, Kochi Prefecture. It lies in the upper reaches of the Kozonso River, a tributary of the famous Shimanto River, and is characterized by exceptionally clear, transparent waters. While summer offers a refreshing escape with cool waters from the mountain springs, autumn transforms the entire valley into a masterpiece of vibrant colors. It is a place where you can experience profound silence and unparalleled natural beauty simultaneously.
This area preserves the rich, untouched natural environment of the Shimanto River basin. The Kozonso River, as a vital tributary, sustains the local ecosystem and the surrounding landscape. The topography, shaped by features such as Mt. Hachimen and Sanbongu, has fostered a long-standing coexistence between humans and nature. As tourism development progresses, the area maintains a delicate balance between welcoming visitors and preserving its pristine natural heritage.

The most iconic view is found around "Shinden Bridge." From the bridge, you can gaze down at the crystal-clear river surface and the lush greenery surrounding it. Depending on the weather and sunlight, the water can even sparkle with a golden hue. A short walk from Shinden Bridge leads to the "Momiji Bridge" (Maple Bridge), a parking area, and the trailhead for Sanbongu, making it an excellent base for exploration. The scenery changes dramatically with each season, ensuring a unique experience every time you visit.
Autumn is the most spectacular season for a visit. From early to mid-November, the valley is bathed in brilliant hues of red, orange, and yellow. Visiting during daylight hours, especially when the sunlight is bright but not too harsh, will allow you to see the beautiful reflections on the water's surface. In summer, the cool mountain waters provide a refreshing retreat from the heat. To fully appreciate the changing face of the valley, we recommend visiting during these peak seasonal transitions.

The primary activity in Kozonsokei Valley is nature walking and hiking. The trail from Shinden Bridge toward Sanbongu is a journey of approximately 3.5 hours. Walking through the forest allows you to breathe in the deep, fresh mountain air and observe the local flora. While it is not a rigorous mountain climb, the environment is perfect for leisurely hiking and contemplative strolls. The high transparency of the river also makes it a wonderful place to simply sit by the water and rest.
The surrounding region is dotted with spots that symbolize the natural beauty of Kochi Prefecture. Nearby, you can find the iconic sunken bridges (Chinkabashi) of the Shimanto River and various natural campsites. The geological landmarks of Mt. Hachimen and Sanbongu are also highly interesting for nature enthusiasts. You can easily incorporate a visit to Kozonsokei into a larger itinerary exploring the Shimanto River basin and other scenic spots in Kochi.
Since this is a natural wilderness area, preparation is essential. Please wear comfortable walking shoes and clothing suitable for hiking on uneven or unpaved paths. Note that mobile phone reception can be spotty in certain areas, so it is wise to download offline maps in advance. As there are very few shops or convenience stores nearby, please bring your own drinks and snacks. To protect this precious environment, please follow all local manners, such as carrying your trash back with you and respecting the natural surroundings.