The pond's water output is enough to supply the daily water needs of approximately 14,000 households.
Water from the pond is diverted into secondary irrigation channels that run through the adjacent village streets.
The water clarity is so high that submerged logs and vegetation are visible from the surface even at the center of the pool.
The pond is part of the 'Maruike-Yusui-no-Mori' park, which was selected as one of the 100 Best Water Sources in Japan by the Ministry of the Environment.
The name 'Maruike' literally translates to 'Round Pond' due to the distinctive circular shape of the basin.
Maruike Pond is a natural spring fed by the volcanic aquifers of the Kirishima mountain range in Yusui, Kagoshima. The pond maintains a constant water temperature of approximately 14 degrees Celsius throughout the year. It serves as the primary water source for the surrounding community, providing a daily output of roughly 22,000 tons of spring water. The water is renowned for its extreme clarity and distinct blue-green hue caused by the geological filtration process. A small wooden shrine stands on the water's edge, integrated into the local landscape. The surrounding park area includes wooden walkways to protect the natural spring basin. Local regulations strictly prohibit swimming or fishing in the pond to preserve water quality. The area serves as a designated regional heritage site representing the traditional water usage culture of the Aira District.
The wooden viewing deck positioned directly over the water provides an unobstructed view into the depths of the pond.
Bring a reusable water bottle to fill up at the designated drinking water taps located near the entrance.
Wear comfortable walking shoes with good grip, as the wooden paths can become slippery when damp.
Combine the visit with a walk through the neighboring village to see the historic irrigation canals fed by the pond.
Do not attempt to walk on the grassy banks surrounding the water where signs prohibit entry, as this damages the fragile ecosystem.
Do not enter the water, wash hands or feet in the pond, or discard any items into the spring; observe the designated walking paths.
