Japan is home to countless natural wonders, but few are as mysterious and fleeting as Kagami Numa, also known as the “Dragon’s Eye Lake.” Hidden near the summit of Mount Hachimantai in northeastern Japan, this volcanic lake appears ordinary for most of the year. Yet, in late spring, it undergoes a remarkable transformation that draws visitors from near and far. For just a short window of time, the melting snow and shifting waters turn the lake into what looks like a giant dragon’s eye gazing up from the earth.
Kagami Numa is a mythical lake in Japan that transforms into a giant eye each spring due to the melting of ice.
Located near the summit of Mount Hachimantai in northeastern Japan, deep within a dense forest, Kagami Numa looks much like many other volcanic lakes in the region. But for about one week, from late May to early June, it reveals a striking “giant blue eye” that resembles the eye of a dragon.
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The lake’s unusual appearance during this short period has inspired local folklore. According to legend, two dragons in love chose these waters as their secret meeting place.
While many enjoy the mythical tale, science offers a simple explanation. In spring, as the snow and ice begin to melt, water pressure causes the remaining snow to gather in the center of the lake. This creates a white core surrounded by a ring of clear blue water, resembling a pupil and iris.
When the wind blows, the ice and snow at the center rotate, giving the impression of a moving pupil. This fascinating natural phenomenon has become a seasonal spectacle. Unsurprisingly, people from across Japan—and even from abroad—flock to Mount Hachimantai in late spring to witness it firsthand.
In recent years, photographs shared online and a video published by the BBC have only increased Kagami Numa’s popularity, making it a must-see destination for travelers intrigued by both nature and legend.
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Whether viewed through the lens of folklore or science, Kagami Numa’s Dragon’s Eye is a rare natural spectacle worth experiencing. The phenomenon lasts only about a week each year, making it a truly special sight for those who plan their visit carefully. For travelers exploring the Tohoku region in late spring, this hidden lake offers a glimpse into both the beauty of nature and the cultural stories it inspires.
