Mount Bandai's eruption on July 15, 1888, was not a typical volcanic event. Rather than spewing lava, the north face of the mountain simply collapsed in a massive phreatic explosion -- a steam-driven blast triggered when groundwater met superheated rock. The landslide that followed destroyed dozens of villages and killed 477 people. It also completely reshaped the terrain north of the volcano, damming rivers and streams with volcanic debris to create the Bandai-kogen plateau and hundreds of new lakes and tarns scattered across it. The eruption was one of the most destructive in modern Japanese history, and the landscape it left behind -- raw, mineral-rich, and studded with water -- became the foundation for an entirely new ecosystem. Among the hundreds of bodies of water that formed, five would prove extraordinary.

The five main lakes -- Bishamon-numa, Aka-numa, Ao-numa, Benten-numa, and Midoro-numa -- each contain a distinct combination of volcanic minerals deposited by the 1888 eruption. These minerals interact with sunlight, water depth, and algae to produce strikingly different colors in each pond. Bishamon-numa, the largest of the five, tends toward deep blue-green. Aka-numa leans reddish, true to its name (aka meaning red in Japanese). Ao-numa runs toward blue. But what makes the ponds genuinely mysterious is that their colors are not fixed. They shift throughout the year, responding to temperature, weather conditions, dissolved mineral concentrations, and biological activity in ways that remain incompletely explained. A pond that looks turquoise in summer might turn a murky green in autumn. Visitors who return in different seasons see what appears to be an entirely different set of lakes.

A four-kilometer nature trail connects all five lakes, running from Bishamon-numa to Lake Hibara through dense forest and along boardwalks that skirt the pond edges. The path is gentle enough for casual hikers and takes roughly 70 to 90 minutes to complete at a leisurely pace. Each pond appears suddenly through breaks in the trees, and the effect is startling -- stepping from the cool shade of forest into a clearing where the water blazes an impossible shade of blue or green. The surrounding forest, largely regrown since the eruption, is a mix of deciduous and coniferous trees that adds its own seasonal color. In autumn, the contrast between fiery red maple leaves and the mineral blues and greens of the ponds creates combinations that look almost artificial. The area is part of the broader Bandai-Asahi National Park and sits at the heart of the Urabandai lake district, one of the most popular outdoor recreation areas in the Tohoku region.

There is something unsettling about how beautiful Goshiki-numa is. The ponds exist because hundreds of people died, because a mountain exploded, because the rivers were blocked by debris from one of Japan's worst volcanic disasters. The villages that once occupied this highland are gone, buried under meters of volcanic sediment. Yet the landscape that replaced them draws hundreds of thousands of visitors each year -- hikers, photographers, and families on holiday. The Bandai-kogen plateau, which did not exist before 1888, is now one of Fukushima Prefecture's most beloved natural areas. The Five Colored Ponds, born from destruction, have become symbols of renewal. Japan has long understood this duality -- that the same volcanic forces that destroy also create -- and Goshiki-numa embodies that understanding in five small, impossibly colorful pools of water.