The surrounding beech forest acts as a natural water filtration system, storing rain and snowmelt in volcanic soil layers for decades.
The water clarity is attributed to the low mineral content and high oxygen saturation typical of the Daisen volcanic massif.
Suntory's Okudaisen Bunkasui plant operates nearby, drawing from the same hydrological system as the creek.
The area is specifically noted for the variety of bryophytes (mosses) that thrive in the constant humidity provided by the creek and forest canopy.
Kitani-sawa Creek is a hidden stream located within the Okudaisen region, renowned as the source of natural mineral water used by Suntory for its 'Minami-Alps Tennensui' brand. The creek features moss-covered stones and dense beech forests that filter rainwater into high-purity groundwater. A wooden boardwalk allows visitors to traverse the area without damaging the fragile ecosystem. The water maintains a constant temperature of approximately 9 degrees Celsius throughout the year. It is situated on the slopes of Mount Daisen, Japan's largest beech forest area. Visitors can observe the vivid green moss covering volcanic rocks along the crystal-clear water path.
The mid-point of the boardwalk where the creek curves, offering a clear view of the moss-covered boulders against the stream.
Wear waterproof, non-slip hiking boots as the boardwalk and surrounding volcanic rocks are constantly damp and slippery.
Bring mosquito repellent, as the humid, forested environment attracts insects during the warmer months.
Stick strictly to the designated boardwalk to avoid disturbing the moss and fragile riparian soil.
Attempting to walk off the path to get closer to the water, as the riverbanks are unstable and ecologically sensitive.
Access is difficult or restricted during heavy winter snowfalls; check local Daisen area road conditions before traveling between December and March.
Carry out all trash, remain on the wooden path, and maintain a quiet volume to respect the protected natural environment.
