Guide
Oku-Shima Lake is a breathtakingly beautiful body of water located deep within the Shima Onsen area. Its most defining characteristic is the mystical "Shima Blue"—a vibrant, translucent cobalt blue water surface. This phenomenon is caused by the high level of water clarity and the way light scatters across the surface. This natural masterpiece offers a sense of serenity that allows visitors to escape the stresses of daily life.
The lake is deeply intertwined with the surrounding topography and natural environment, long cherished as a symbolic landscape of the region. The extreme clarity of the water serves as a testament to the pristine environmental health of the area. This stunning scenery has also gained significant attention in Japanese media and advertising, recognized not just as a scenic spot, but as a quintessential symbol of Japan's untouched natural beauty.
The absolute highlight of Oku-Shima Lake is observing the "Shima Blue" in person. On clear mornings when sunlight pours onto the lake, the water transforms into a brilliant, glowing cobalt blue, offering its most spectacular expression. The area features well-maintained walking paths and observation decks, allowing you to enjoy the breathtaking views from various angles. Because the water is so clear, you can often see deep into the depths, making the view feel like a living piece of art.
The appearance of Oku-Shima Lake changes completely depending on the season and time of day. From April to May, as snowmelt flows into the lake, the water becomes exceptionally clear and the blue color appears even more vivid. The autumn season, from mid-October to early November, is also highly recommended, as the vibrant colors of the surrounding foliage create a stunning contrast against the blue water. For the most brilliant light reflection and the most intense blue, aim to visit on a sunny morning.
You can fully immerse yourself in nature through various activities along the lakeshore. A particularly popular experience is canoeing; being close to the water's surface allows you to feel the magic of the "Shima Blue" from a unique perspective. Gliding through the quiet, still waters provides a luxurious sense of peace and unity with nature. Simply strolling along the perimeter of the lake to watch the scenery shift is another wonderful way to enjoy this location.
The area surrounding the lake is rich in nature, with several spots perfect for relaxation and light hiking. The routes around the lake are equipped with observation decks designed for taking in the scenery, making it easy to spend a peaceful afternoon. There are also nature-themed parks in the vicinity, making this a great destination for families and nature enthusiasts looking to unwind in a tranquil environment.
As this is a natural area, we strongly recommend wearing comfortable walking shoes and clothing suitable for the weather. If you plan to enjoy canoeing, please bring activewear. To protect the environment, please ensure you carry all your trash home with you. Weather conditions can change quickly, so it is wise to prepare for the specific season during your visit.