Goshikinuma Pond Group The Goshikinuma (lit., “colorful marshes”), are a cluster of about 30 ponds known for their turquoise, green, and copper hues. Around 300 of these shallow bodies of water formed following an eruption of Mt. Bandai in 1888. The eruption sent tons of debris cascading down the mountain’s northern slopes. The ponds formed in depressions that remained when the debris dammed several valleys.
The vivid, multicolored shades are believed to be caused by chemicals and mineral particles such as aluminum silicate in the water and sand. The colors are also affected by reflections of the surrounding landscape and differences in sediment and vegetation. Some of the ponds are very acidic, due to high levels of sulfates in the water, which is the result of the mountain’s volcanic activity. Some have a pH so low that they cannot support aquatic life.
Geologists believe water filters through to these ponds from lakes at higher altitudes. The Copper Pond (Akanuma) is a crater lake high on the northern slopes of Mt. Bandai. It is thought to be the source of springs that feed some of the ponds and affect their mineral content.
The 90-minute walk along the Goshikinuma Pond Trail passes 10 of these ponds.
Bishamonnuma (Goshikinuma Pond Group) Bishamonnuma is the largest of the Goshikinuma ponds, a colorful cluster of around 30 shallow ponds and marshes formed when Mt. Bandai erupted in 1888 and triggered a landslide that dammed a nearby river.
Bishamonnuma appears either blue or green, depending on the light. The pond’s relatively low acidity allows plankton and aquatic plants, such as watermilfoil (Myriophyllum) and pondweed (Potamogeton) to flourish. Several species of fish, including Amur minnow and Japanese dace thrive here.
Bishamonnuma is the first pond encountered walking westwards along the trail that leads from the Visitor Center. It is the only pond on the trail at which you can hire a paddle boat for views from the water. The pond's name comes from Bishamon, one of the four guardian deities in the Buddhist pantheon, and also one of Japan’s Seven Lucky Gods, which have been worshipped since the Muromachi period (1336–1573).
Akanuma (Goshikinuma Pond Group) Akanuma (Red Pond) is part of the Goshikinuma Pond Group, a colorful cluster of around 30 shallow ponds and swamps formed when Mt. Bandai erupted in 1888 and triggered a landslide that blocked a nearby river.
It is fed by spring waters originating in the acidic, iron-rich Copper Pond (also named Akanuma), a crater lake high on the northern slope of Mt. Bandai. The water, despite the pond's name, usually appears greenish with only slight red hues. The red comes from iron-rust residue that accumulates on the roots of the reeds and other aquatic plants growing in the pond.
Midoronuma (Goshikinuma Pond Group) Midoronuma Pond (Deep Mud Pond) is part of the Goshikinuma Pond Group, a colorful cluster of around 30 shallow ponds and swamps formed when Mt. Bandai erupted in 1888 and triggered a landslide that blocked a nearby river.
Midoronuma is one of the smallest bodies of water on the Goshikinuma Trail. The pond is fed by multiple underground springs, varying the colors within the pond and creating a dappled effect. Color gradients range from blue-green or yellow-green to electric blues depending on variations in water quality, plant life, and the quality of the light.
Tatsunuma (Goshikinuma Pond Group) Tatsunuma (Dragon Pond) is part of the Goshikinuma Pond Group, a colorful cluster of around 30 shallow ponds and marshes formed when Mt. Bandai erupted in 1888 and triggered a landslide that blocked a nearby river.
Tatsunuma is a vibrant blue-green color. The pond is surrounded by thick forest, meaning only glimpses of it are visible from the Goshikinuma Pond Trail.
Bentennuma (Goshikinuma Pond Group) Bentennuma is the second largest of the Goshikinuma ponds, a colorful cluster of around 30 shallow ponds and marshes formed when Mt. Bandai erupted in 1888 and triggered a landslide that blocked a nearby river.
This blue, green, and milky white pond is one of the less acidic ponds of the group, so it is more likely to freeze over during the winter. A species of moss that grows in the pond, Drepanocladus fluitans, forms dense mats along the bottom.
The pond is named after Benten, the Buddhist goddess of water and the arts, one of Japan’s Seven Lucky Gods worshipped since the Muromachi period (1336–1573).
Rurinuma (Goshikinuma Pond Group) Rurinuma (Lapis Lazuli Pond) is one of the Goshikinuma ponds, a colorful cluster of around 30 shallow ponds and marshes formed when Mt. Bandai erupted in 1888 and triggered a landslide that blocked a nearby river.
Rurinuma is a blue, green, and milky white pond. Experts believe this unusual color may come from the high levels of calcium and sulphate ions in the water. Drepanocladus fluitans moss growing in a rare mat formation on the pond floor may also affect the color. Like Bentennuma and Aonuma, this pond is fed by water from the highly acidic Copper Pond, a crater lake located high on the northern slope of Mt. Bandai. As a result, there is little plankton growth or aquatic life.
Aonuma (Goshikinuma Pond Group) Aonuma (Blue Pond) is one of the most striking of the Goshikinuma ponds, a colorful cluster of around 30 shallow ponds and marshes formed when Mt. Bandai erupted in 1888 and triggered a landslide that blocked a nearby river.
Aonuma’s deep blue color contrasts beautifully with both summer greens and autumn foliage. Plants overhanging the pond appear frosted where they have dipped into the water. This is due to a coating of aluminum silicate, an acidic compound in the water deposited during the eruption. Aluminum silicate is present in other lakes within the Goshikinuma cluster, but to a lesser degree.
The pond is too acidic for plankton or fish, but it supports extensive mats of moss called Drepanocladus fluitans.
Yanaginuma (Goshikinuma Pond Group) Yanaginuma (Willow Pond) is one of the Goshikinuma ponds, a colorful cluster of around 30 shallow ponds and marshes that formed when Mt. Bandai erupted in 1888 and a subsequent landslide blocked a nearby river.
Yanaginuma is one of the largest of the Goshikinuma ponds. This emerald green pond has relatively mild acidity levels, meaning it can support plankton and other pond life, including fish such as Japanese dace (Tribolodon hakonensis) and wakasagi smelt (Hypomesus nipponensis).
Mt. Bandai Mt. Bandai is a 1,816-meter stratovolcano, a volcano built up of layers of lava and ash, that has been dramatically reshaped by two large eruptions.
Around 2,500 years ago, Mt. Bandai was symmetrical, but volcanic activity caused the peak to collapse in on itself, creating the Numanodaira Caldera.
In 1888 it erupted again in a devastating steam-blast eruption, an explosion that occurs when water beneath the ground or on the surface is heated by magma or lava. No lava was discharged, but it was powerful enough to cause the collapse of one of the volcano’s four peaks, Ko Bandai (around 1,800 meters, on the north side of the mountain), and triggered a large-scale landslide.
The landslide destroyed 11 communities and entirely reshaped the north side of the mountain, known today as Ura-Bandai. The landslide that followed destroyed entire villages and dammed up valleys, forming around 300 lakes and ponds. Today, their beauty is a major attraction in Bandai-Asahi National Park.
Vegetation in the area was badly damaged but grew back quickly, in part because of extensive, government-backed reforestation projects. A lava eruption would have likely caused more long-term damage to the ecosystem.
Six trails of varying difficulty lead to the top of the mountain. From the top you can see where Ko Bandai collapsed and the surfaces of lakes and ponds. Since the early seventh century, these trails have been used by practitioners of Shugendo, a folk-religion based on mountain worship, that involves enduring extreme physical hardships. During climbing season, between late May and October, you can follow their footsteps up the mountain’s trails.
Mt. Bandai is made up of hardened layers of lava, ash, pumice, and fragmented rock. Its partial collapse offers a rare opportunity to see a cross-section of this type of volcano, which makes it an important geological site. Mt. Bandai now consists of three peaks, O Bandai (1,816 meters), Kushigamine (1,636 meters) and Akahaniyama (1,430 meters).
Akanuma (Copper Pond) Akanuma (Copper Pond) is a rust-hued, horseshoe-shaped crater pond, created during the eruption and partial collapse of Mt. Bandai in 1888. It lies in a forested caldera on the northern flanks of the now inactive volcano.
High levels of iron hydroxide in the lake give the pond its coppery red color. The acidity levels are too high to support aquatic life. Fumaroles, openings in the side of Mt. Bandai visible from the pond, emit gases.
Akanuma (Copper Pond) has an elevation of over 1,000 meters above sea level. Geologists believe its water seeps downward through the earth and emerges at lower altitudes as springs that run into the colorful Goshikinuma cluster of ponds some 300 meters below, one of which is similarly named Akanuma (Red Pond). Minerals enter the lakes in varying quantities, altering the color, acidity, and ecosystem of each pond. When Akanuma (Copper Pond) freezes over, you can hire a guide to show you a safe route to its “Yellow Falls,” a frozen waterfall with a golden, sulfur color.
Lake Hibara Lake Hibara is the largest lake in the Bandai Kogen Highlands, covering 10.7 square kilometers. It was formed during the 1888 eruption of Mt. Bandai. The landslide that followed destroyed entire villages and dammed up valleys, forming around 300 lakes and ponds.
On the northern shore of the lake there is a torii gate from Oyamazumi-jinja Shrine that survived the eruption. Another torii gate from the same shrine is submerged in the lake, occasionally piercing the surface when water levels drop. Small islets dotting the lake are comprised of volcanic debris from the eruption.
The lakeside is popular for camping, with several campsites along the shore. There is a path around parts of the lake that is ideal for walking or cycling. Between late April and late November, explore the lake from the water by speed boat, or hire a canoe or pedal boat. Ice fishing for smelt is a popular pastime after the lake freezes over.
Nakasenuma Pond Nakasenuma Pond was formed during the powerful 1888 eruption and partial collapse of Mt. Bandai. The event displaced vast quantities of soil and rock. This debris blocked river systems and created debris flow deposits. Water flooded into the depressions and deposits, creating around 300 lakes and ponds, including Nakasenuma Pond.
You can see the pond and Mt. Bandai from an observation deck, a stop on the Rengenuma Pond hiking trail (700 m) and Nakasenuma Pond trail (1.2 km).
The observation point is a prime place for birdwatching. Species that inhabit the area include several varieties of flycatcher and bunting.
Oguninuma Oguninuma is a lake that formed 400,000 years ago when nearby Mt. Nekomadake erupted and partially collapsed. The lake is famous for its surrounding wetlands, which are designated a National Natural Monument. Mid-June is the best time to see azaleas and late June to early July is the best time to see bright yellow daylilies bloom here. An 800-meter boardwalk runs through the marshes and around the pond.
The Oguninuma Marshland Trail can be reached from either the Oguni Seseragi Trail or the Oguni Panorama Trail.
Onogawa Fudo Falls Onogawa Fudo, fed by nearby Hyakkan Shimizu spring, is a large waterfall, 6,000 tons of water a day dropping 25 meters. Since the Heian period (794–1185), the falls have been a source of sacred water and a training ground for practitioners of Shugendo, a Japanese folk religion based on mountain worship that involves enduring extreme physical hardships. Practitioners came here to worship Buddhist deity Fudo Myo-o, and to pray under the icy cold waters of the falls. There is a small, modern shrine near the waterfall.
Onogawa Fudo is surrounded by a forest of Japanese horse chestnut, wingnut, and oak.
The cool mist of the waterfall makes it a popular spot to rest in summer. In winter, the falls freeze and look light blue, and can be accessed on snowshoes and with the assistance of a guide.
Nuno Falls Nunodaki Falls is a multiple drop waterfall fed by water from the surrounding mountains. The falls cascade over 50 meters of rocks through the ravine between Mt. Nishi-Azuma and Mt. Nishi-Daiten, flowing into a small stream that empties into Lake Hibara, one of the largest lakes in Ura-Bandai.
Nuno means “cloth,” evoking the way the water appears to drape over the rocks as it flows. Nunodaki Falls is accessible on foot when descending from the Dekodaira marshlands in the direction of Lake Hibara.
Nakatsugawa Gorge Nakatsugawa Gorge is a 10-kilometer stretch of river lined with ancient forests. These provide some of the most vibrant autumnal colors in the Ura-Bandai area and feature wild cherry trees that flush a light pink in spring. The gorge is home to a thriving population of deer, boar, and Asiatic black bear.
The exposed riverbed is a layer of volcanic rock, which was formed underground, millions of years ago. Over the years, the flow of the Nakatsugawa River gradually eroded the layers of sediment above the rock, exposing it.
The river flows from high in the Azuma Mountains, into the northern end of Lake Akimoto, around a kilometer from the gorge.
Visitors can access the gorge on foot by descending some steep stairs on the trail from Lake Akimoto. The 1.5-kilometer hiking route is suitable for beginners.
Hyakkan Shimizu Spring The Hyakkan Shimizu Spring is a clear spring known for its cool, drinkable water. It is at an altitude of 1,300 meters on a trail between Mt. Nishi-Daiten and Mt. Nishi-Azuma.
The spring is surrounded by towering beech trees and is the source of the Onogawa River and the enormous Onogawa Fudo waterfall. Hikers can refill their bottles using a scoop placed next to the pool.
Mt. Nekomadake Mt. Nekomadake is a 1,404-meter tall inactive volcano. It erupted around 400,000 years ago, causing the collapse of one of its peaks and the formation of lake Oguninuma.
Mt. Nekomadake translates to “evil cat peak.” The name is thought to derive from several cat myths surrounding the mountain. The most common story describes a vicious cat that inhabited the mountain. It would prey on human flesh, disguising itself as a human to lure people closer. Buddhist monk Kukai (posthumous name Kobo Daishi; 774–835), is said to have trapped the cat within a massive pile of boulders on a lower peak of the mountain.
Numanotaira Crater Numanotaira Crater on Mt. Bandai was formed during volcanic activity around 2,500 years ago. Mt. Bandai was a symmetrical volcano, but the top of the mountain collapsed in on itself, creating this 1.2-kilometer wide, 350-meter deep crater. After the collapse, the crater was surrounded by four peaks, O Bandai (1,816 m), Kushigamine (1,636 m), Akahaniyama (1,430 m), and Ko Bandai (1,800 m). Another significant eruption in 1888 caused Ko Bandai to collapse, sending landslides cascading down the northern slopes of the mountain and resulting in the creation of the famous Goshikinuma ponds. Today only three peaks comprise the crater wall. The 1888 eruption also opened vents, called fumaroles, in the crater walls, that emit volcanic gases.
Ura-Bandai’s Reforestation Project The eruption and partial collapse of Mt. Bandai in 1888 was one of the worst natural disasters to occur in Meiji-era (1868–1912) Japan. The landslide triggered by the collapse of one of the volcano’s peaks buried 11 communities and killed 477 people. The surrounding land was left barren.
A reforestation program was launched in the early twentieth century. The government offered an initiative of low-priced land to people who made significant contributions to the area’s reforestation. Endo Genmu (1864–1934), a man from Fukushima Prefecture, came to the forefront of this effort. He traveled from the city of Aizu-Wakamatsu with seedlings via a newly opened railway line. Endo and his collaborator, forestry expert Nakamura Yaroku (1855–1929), are credited with planting some hundred thousand trees over 13.4 square kilometers. Many of the original red pines (Pinus densiflora) they planted can still be seen along the Goshikinuma Pond Trail. These efforts contributed to the now flourishing ecosystem.
Ecological Succession in Ura-Bandai A mature and diverse forest is developing out of the wasteland that was left in the wake of the enormous eruption and partial collapse of Mt. Bandai in 1888. The thick forests growing here today are the result of reforestation and natural vegetation recovery, known as ecological succession. This multi-decade process begins with the emergence of “pioneer species” that nourish the soil and encourage the growth of other plants, and the migration of animal species from surrounding habitats. Next to emerge are fast-growing, light-loving shrubs and trees, and finally, more resilient trees, such as beech.
Mammals of Ura-Bandai Ura-Bandai’s abundant wildlife is an indicator of how well its forests and ecosystems have recovered since the eruption and partial collapse of Mt. Bandai in 1888. Approximately 40 mammal species inhabit the area, including the native subspecies of the Asiatic black bear and the stoat, as well as native species of macaque monkey, serow, and squirrels.
Birds of Ura-Bandai A wide variety of birds live in the Ura-Bandai area. Japanese green woodpeckers (Picus awokera), Bohemian waxwings (Bombycilla garrulus), ruddy kingfishers (Halcyon coromanda), Siberian blue robins (Luscinia cyane), and narcissus flycatchers (Ficedula narcissina) have all been spotted here. Ura-Bandai is recognized as an Important Bird Area (IBA) by BirdLife International and its bird populations are protected.
Plants of Ura-Bandai A wide variety of plant life flourishes in Ura-Bandai’s open wetlands, high-mountain grasslands, and dense forests. Azaleas and dense fields of zenteika (also called nikko kisuge) daylilies (Hemerocallis middendorffii) flower in the marshland surrounding lake, Oguninuma, between mid-June and late June to early July, respectively. Higher on the slopes, severe cold and strong winds during the winter months make it difficult for even hardy alpine plants to thrive. However, the blue-violet Bandai speedwell (Veronica schmidtiana) is one species that has adapted to the harsh environment. Other notable plants seen here are skunk cabbage (Symplocarpus nipponicus), found near many of Ura-Bandai’s ponds, and a type of moss (Drepanocladus fluitans) that forms dense mats in some of the more acidic Goshikinuma ponds.
Aquatic Life in Ura-Bandai The majority of the 300 lakes and ponds formed in Ura-Bandai during the 1888 eruption support aquatic biodiversity, including fish such as smelt, dace and minnow, insects like the predacious diving beetle (Dytiscidae), and the Bandai clawed salamander (Onychodactylus intermedius).
Insects of Ura-Bandai The marshlands and lakes of Ura-Bandai are home to numerous species of dragonfly, with 61 species sighted in the area. This includes the Siberian hawker (Aeshna crenata), and the dainty Platycnemis echigoana featherleg damselfly. There are more than 90 identified species of butterfly, including the chestnut tiger (Parantica sita). Various threatened species live here, such as the gengoro diving beetle (Cybister japonicus) and the himeshijimi or silver-studded blue butterfly (Plebejus argus) and several species of firefly, including both the well-known Heike-botaru (Aquatica lateralis) and Genji-botaru (Luciola cruciata), named after two famous warrior families from the twelfth century.
Ura-Bandai in Spring Spring arrives in Ura-Bandai between the end of April and early May, a little later than most of the country. One of the most spectacular spots to witness the changing of the season is at Lake Hibara. In spring, take a boat out to one of its small islets, where cherry trees flourish with blossoms.
Ura-Bandai in Summer From late spring to summer, the Ura-Bandai landscape turns a lush green, but stays relatively cool, making the region ideal for hikes in the mountains or walks in the shaded areas around the plentiful lakes and ponds. Seasonal highlights include bright yellow daylilies that bloom from late June to early July and azaleas that bloom in mid-June around the wetlands surrounding lake, Oguninuma.
One of the most popular hikes during the warmer months is the short walk to Onogawa Fudo Falls. The area around the falls is well shaded and the rushing water enhances the cooling-off experience.
Ura-Bandai in Fall Ura-Bandai bursts into color in the fall and the Goshikinuma ponds are particularly attractive in this season. The blues and greens of the water contrast beautifully with the brilliant tones of the nearby trees.
Nakatsugawa Gorge is famous for its autumn colors. Nakasenuma Pond is also beautiful when the fall leaves are at their peak between October and November. The lookout over the swamp provides reflections of the foliage as well as unobstructed views of Mt. Bandai.
Ura-Bandai in Winter In winter, deep snow blankets Ura-Bandai, making the area popular for skiing and snowboarding. Off the slopes, it can be a challenge to walk through the snow without snowshoes, but you can rent them at specialist stores in the area. The Goshikinuma ponds are especially attractive contrasted against the white. Many of these acidic ponds do not freeze over, and the colors of the ponds appear intensified.
Guides are recommended for all winter trails because deep snow covers the paths, making them difficult to follow.
Summer Activities Summer is an excellent time to explore Ura-Bandai’s mountains and lakes with hiking courses of various lengths and difficulties. The forested hike to Onogawa Fudo Falls, with its shaded path, is pleasant even on a warm day. At Lake Hibara canoes, speed, and pleasure boats can be rented for exploring the lake. Paddle boats are available to rent at Bishamonnuma. Campsites are plentiful around the area, particularly around the main lakes.
Winter Activities In winter, the Ura-Bandai region is cold and covered with a thick blanket of snow. Numerous ski resorts with varied runs make it a popular area for winter sports. Snowshoeing is an option, and there are places where you can rent gear and hire guides. With a guide it is possible to walk across Akanuma Copper Pond to see its frozen Yellow Waterfall.
With the exception of the most acidic Goshikinuma ponds, the majority of the 300 lakes and ponds in Ura-Bandai freeze over during winter. On parts of Lake Hibara, the ice is thick enough to support fishing through holes for Japanese pond smelt (Hypomesus nipponensis).
How Mt. Bandai Was Shaped Mt. Bandai was originally a symmetrical stratovolcano, a volcano built up of layers of lava and ash. Volcanic activity 2,500 years ago caused the top of the mountain to collapse in on itself, creating the 1.2-kilometer wide 350-meter deep Numanodaira Caldera. Before the collapse, it had four peaks of between 1,430 meters and 1,816 meters in height: O Bandai, Kushigamine, Akahaniyama, and Ko Bandai.
A phreatic (steam-blast) eruption in 1888 destroyed the former summit of Ko Bandai or “Little Bandai.” The blast left the mountain with only three peaks, triggered a devastating landslide, and cast debris throughout the area. Hikers to this now inactive volcano can see where the collapse of Ko Bandai occurred and look out across the surrounding area with its many ponds and lakes (around 300) that were formed when the landslide blocked river valleys.
The mountain is carefully monitored for activity to predict and prepare for any future eruptions.
The Colors of the Goshikinuma Ponds The Goshikinuma ponds are a cluster of some 30 bodies of water that formed in Ura-Bandai following the 1888 eruption of Mt. Bandai. The name translates to “colorful ponds,” because of their variety of hues that vary with the season and weather. They can take on shades of turquoise, emerald, or copper-red. The vivid colors are influenced by the mineral composition of the water and types of bottom sediments and vegetation, which differ from pond to pond. In addition, the perceived color changes according to natural lighting, making every visit a different experience.
Terrain Changes Following the Eruption The eruption of Mt. Bandai in 1888 caused the collapse of one of its peaks, Ko Bandai, on its north side. This triggered a landslide that buried entire villages and blocked the flow of a major river, causing wide-spread flooding. Some 300 lakes and ponds, including Lake Hibara, Lake Onogawa, and the famous Goshikinuma ponds, formed in the debris backed up behind the blockage, changing the landscape entirely. Hikers in the Ura-Bandai area today can see evidence of the destruction caused, including a submerged shrine torii gate in Lake Hibara and a clear cross-section of Mt. Bandai where part of it collapsed.
Ura-Bandai Visitor Center’s Snow Room A snow room cools the Ura-Bandai Visitor Center’s interior during warmer months. The room is piled high with compacted snow collected throughout the winter. Air from the Visitor Center is piped into the snow room to cool it, then piped back into the center, using a simple ventilation system. This cools the center naturally, without the need for air conditioners. Visitors can see the snow through the chamber’s viewing window.
The Human Story of the Eruption of Mt. Bandai The eruption of Mt. Bandai on July 21, 1888 led to the deaths of 477 people and the displacement of many others. The eruption was a phreatic (steam-blast) explosion, which caused one of the volcano’s four peaks to collapse and triggered a devastating landslide. Eleven communities were buried in the landslide and an enormous amount of debris was cast throughout the Ura-Bandai area. Some of the debris dammed up the Nagase River, a major waterway in the area, and caused widespread flooding. More than 300 lakes and ponds formed in the debris behind the dammed river.
A torii gate is submerged in Lake Hibara, part of Oyamazumi Shrine. When water levels are low, you can sometimes see the upper part of the gate above the surface.
After the devastation, a concerted effort was led by the national government to replant the forests and help the area recover. Significant progress was made, and in the 1950s, the area became popular for sightseeing and was formally named Bandai-Asahi National Park.
The park attracts visitors for its cool weather, beautiful ponds and abundance of hiking trails, campsites, and activities.
