The pond's intense blue color is caused by the scattering of light within the high-clarity, mineral-rich spring water.
The submerged trees do not decay quickly because the spring water maintains a year-round low temperature that inhibits microbial activity.
Maruike Pond is classified as a 'Maruike-sama' (Lord Maruike), reflecting its historical status as a deity-enshrined water source.
The pond is fed entirely by subterranean water from Mount Chokai, meaning it has no visible surface streams flowing into it.
It is located adjacent to a sister pond, Ushiwatashi, which is fed by the same spring system but appears clear rather than blue.
Maruike Pond is a natural spring-fed pool in the Yuza area of Yamagata Prefecture, characterized by its distinct, vivid cobalt-blue water. The water originates from the snowmelt of Mount Chokai, which filters through volcanic strata to emerge as a spring. Fallen Japanese beech trees submerged in the pond remain preserved by the constant cold water temperature and high transparency. The pond is situated within the grounds of the Maruike-sama shrine, a site historically significant to local mountain worshipers. Its high clarity allows for a mirror-like surface that reflects the surrounding dense woodland. The environment is maintained as a sacred natural site, requiring visitors to observe silence. It is one of the few places in the region where the groundwater composition creates such an intense blue hue.
The wooden viewing platform on the edge of the pond offers the widest angle for capturing the color contrast.
Bring a polarizing filter for your camera to better capture the depths of the pond through the reflective surface.
Wear insect repellent, as the surrounding forest and wetland area are home to significant mosquito populations in summer.
Visit on a calm day; ripples from wind or rain disturb the mirror-like reflections that define the site's aesthetic.
Do not attempt to walk on the fallen logs in the water, as they are fragile and the site is strictly protected.
Maintain silence as it is a sacred religious site; do not touch the water or step off the designated viewing paths.
