Biei's iconic scenic spot, "Blue Pond" | Why is it blue? Is it really not blue? Scenery in all four seasons | Hokkaido Lab - A comprehensive Hokkaido travel guide to enjoy gourmet food, nature, and culture - Hokkaido Lab - A comprehensive Hokkaido travel guide to enjoy gourmet food, nature, and culture

Biei's iconic scenic spot, "Blue Pond" | Why is it blue? Is it really not blue to some? Scenery throughout spring, summer, autumn, and winter.

: Furano, Biei, Tomamu

: Last updated: September 13, 2026

The Blue Pond, a representative scenic spot in Biei, Hokkaido, is a place that many people are drawn to and want to visit at least once, captivated by its vibrant cobalt blue surface. The Blue Pond is a mysterious place born from the convergence of volcanic activity and the serendipity of nature. This time, we will introduce in detail the secrets behind why the Blue Pond is blue, and the highlights of each season, from its appearance in the spring when the snow melts, to its translucent blue in summer, its contrast with the autumn foliage, and its fantastical scenery enveloped in snow in winter.

Table of contents

Why is it blue? A mysterious color born in the foothills of Mount Tokachi.

The beautiful blue pond in every season: spring, summer, autumn, and winter

Access and basic information about the Blue Pond

Why is it blue? A mysterious color born in the foothills of Mount Tokachi.

The reason the Blue Pond is blue is the same reason the sky is blue.
Sunlight, which consists of light of various colors, scatters in different directions depending on the color when it hits tiny particles in the air or water. Blue light, in particular, scatters easily, which is why the sky and sea appear blue.

The reason the Blue Pond is blue is basically the same reason the sky is blue.
A combination of several coincidences has created conditions underwater that make it easy to reflect sunlight.

Below is a more detailed explanation of the mystery of the blue color.

The Blue Pond is actually an artificial pond. It was formed when a dam was built on the main stream of the Biei River to prevent volcanic mudflows from the active volcano, Mount Tokachi, and water accumulated behind the dam. It was, in a sense, a by-product of disaster prevention work.
Biei Blue Pond, Shirohige Falls

▲Biei River and Shirahige Falls▲

Due to the influence of the active volcano, Mount Tokachi, the groundwater in the area contains a large amount of aluminum. When this volcanic groundwater flows into the Biei River from places like Shirahige Falls, the river's flow and the action of the waterfalls mix the river water with the aluminum and other substances in the groundwater, creating a condition where the water reflects sunlight easily.

Furthermore, the sulfur and lime derived from the Shirogane hot springs stain the bottom of the pond white, which is said to be a factor in making sunlight more easily reflected, thus making the blue color of the pond water stand out even more.

Disappointed?! Here's when the Blue Pond isn't "blue"

Biei Blue Pond
Bad weather and little sunlightIn some cases,The river is swollen due to rain and snowmelt.At that point, the blue color fades and the appearance becomes cloudy or whitish.

Best time to visit the Blue Pond

for that reasonThe best conditions for visiting the Blue Pond are sunny days when the snowmelt water has stabilized in the river, and the river water level is stable..
June and October, with no snowmelt and a high percentage of sunny days, are arguably the best seasons to visit.

The blue pond changes color in countless ways depending on the delicate and subtle nuances of its hues. What color will you encounter?

Next page: Beautiful Blue Pond in each season: Spring, Summer, Autumn, and Winter