Kagami Numa Lake is located near the summit of Mount Hachimantai in the border area between Iwate and Akita prefectures. It is one of the most spectacular and rare natural phenomena, visible only during a specific season. The serene alpine water body lies undisturbed throughout much of the year, under a blanket of mountain underbrush and winter snow. In a short two-week season in late spring, when the ice melts, the basin becomes the world-famous “Dragon Eye” (Ryu-no-me).
In spring, when the sunlight glints on the edges of the snowdrift, leaving a frozen eye in the middle like a pupil, Kagami Numa Lake presents a striking and gigantic blue-and-white eye looking up at the sky. Towada-Hachimantai National Park is a popular destination for outdoor enthusiasts, offering a glimpse into this optical phenomenon.
Table of Contents
- Story about geography and the science behind the Dragon Eye
- Understanding these dynamic forces to visit Kagami Numa Lake
- Step 1 – Keep an eye on the thaw and time your visit
- Step 2: Choose Your Favourite Trail Strategy and Route
- Step 3: Ensure regional transportation and road conditions
- Step 4: Pack Equipment specifically for Snowmelt & Cold Alpine Air
- Step 5: Do the Trail Navigation Safely.
- Step 6: Practice Environmental Conservation
- Route Summaries and Profiles
- Best Seasons to Visit
- Planning to Travel in the North of Japan.
- How We Would Time a Dragon Eye Visit
- Kagami Numa FAQ
- Sources and Last Check
Story About Geography and the Science Behind the Dragon Eye
Knowing the special geology and atmosphere of the area will help you understand why Kagami Numa Lake is so ephemeral.
Kagami Numa is a small crater pond at an elevation of about 1,600 m, along the walking trail near the Mount Hachimantai summit (the plateau summit itself is 1,613 m). It sits among wetlands, ponds and Maries’ fir forest, and the ponds in this area were formed by past volcanic activity.
Snow Accumulation Phase: Heavy winter storms bring meters of heavy snow to the Towada-Hachimantai range, and the lake is covered in a deep, compact snowpack.
The Spring Thaw: In late May, rising temperatures and meltwater from the surrounding snow start to open the pond. According to the Hachimantai tourism body and the Ministry of Land, Infrastructure, Transport and Tourism, the snow and ice around the edge thaws first, opening a ring of blue water, while an island of snow and ice remains in the centre like a pupil. Later, the centre thaws as well and the “eye” closes up. How fast this happens depends on each year’s snowfall, temperature and weather.
The Blue Ring: In clear weather the open water reflects the sky, which is why the ring looks such a vivid blue. The colour and shape change with the light and weather, so no two days look exactly the same.
Understanding these Dynamic Forces to Visit Kagami Numa Lake
Step-by-Step Method: How to Carry Out a Risk-Free and Effective Trip
When visiting a high-elevation wetland habitat during the spring thaw, it is important to plan, use the right equipment, and treat the fragile alpine land with care. Use the following 6 safety steps to make your trip safe.
Step 1: Keep an Eye on the Thaw and Time
The Dragon Eye is usually visible for about two weeks, from late May into mid-June, and the exact dates shift every year with snowfall and weather. Akita Prefecture runs an official “Hachimantai Dragon Eye” information page with dated photo updates through the season, and the Hachimantai Visitor Center can tell you the current state of the snow. Check both before you leave. Come too early and the pond is still a plain white snowfield; come too late and the central island of snow and ice has already melted. Weekdays are calmer: traffic can back up on the Hachimantai Aspite Line during the peak weeks.
Step 2: Choose Your Favourite Trail Strategy and Route
Select a walking route that is appropriate for your time, equipment, and fitness.
Option A: The Hachimantai Summit Loop (Easy – 1.0 to 1.5 Hours) is probably the most popular route, beginning at the parking lot of the Hachimantai Rest House. A paved and well-maintained wooden boardwalk loop, this 2.5-kilometre walk leads through Kagami Numa Lake, Megane Numa and the official Mount Hachimantai lookout tower.
Option B: The Hachimantai Nature Trail circuit (about 5 km; allow extra time if snow is still lying). From the same Rest House, the trail passes a string of ponds, then climbs Mount Gentamori and Mount Hachimantai before returning. The Ministry of the Environment’s Towada-Hachimantai page lists this as the area’s signature walking course; ask at the Rest House or the Visitor Center about current snow conditions.
Making your route choice ahead of time helps to keep your party organised and on track.
Step 3: Ensure Regional Transportation and Road Conditions
In late spring, it’s important to check road conditions and travel times when driving over mountain passes.
The main road, the Hachimantai Aspite Line, runs between Iwate and Akita prefectures. It reopens for the season in mid-April (the 2026 opening was scheduled for April 15, weather permitting), and tall walls of snow can still line the road in spring. Cars can park at the Hachimantai Mountaintop Rest House near the pass. Without a car, buses run from JR Morioka Station on the Iwate side; buses from Tazawako on the Akita side run only on certain days (weekends, Obon and the autumn colour season), so check the operator’s current timetable before you plan around them.
Step 4: Pack Equipment Specifically for Snowmelt & Cold Alpine Air
In the spring at 1,500+ meters: rapidly changing weather and slippery, icy conditions.
The area around Kagami Numa Lake is still in snow slush with packed snow during peak viewing hours, so be sure to wear waterproof hiking boots with good ankle support and a good tread. Put micro spikes or light crampons on boots to hold onto icy slopes. Wear a base layer that is moisture-wicking, a fleece or down jacket for warmth, and a windproof/waterproof outer shell. Pack sunglasses to help with the snow glare at high altitudes, trekking poles for balance, and a water bottle.
Step 5: Do the Trail Navigation Safely
Follow the trail, develop the skill of good footwork, and keep an eye on the weather.
At the Hachimantai Rest House, the trail is clearly indicated with directional signs towards the Dragon Eye and the trail to the top. It’s about a 15- to 20-minute walk to the lake, up a gentle slope. If there is springtime mountain fog, walk slowly on the plateau, keeping to trail markers to avoid becoming disoriented on snow-covered trails.
Step 6: Practice Environmental Conservation
It is very important to follow outdoor ethics in order to preserve the Towada-Hachimantai National Park.
Do not leave the trail or walk on the surface of the melting Kagami Numa Lake. The ice sheet is thin and unstable; it is very dangerous. Keep within wooden safety ropes and barrier flags to avoid damaging sensitive alpine vegetation, including plants that are blooming, e.g., Mizubasho (Asian skunk cabbage) and the alpine lilies emerging along the retreating banks. Take out all rubbish; do not alter the natural environment.
After all the aforementioned steps, you may enjoy relaxing in the local Hachimantai Onsen villages.
End your trip in the mountains with a taste of the abundant geothermal hot springs around the mountain base.
Route Summaries and Profiles
Hachimantai Summit Dragon Eye Loop
Stats: 2.5 km | ~1.0 to 1.5 Hours | Elevation Gain: 90 m | Level: Easy-Moderate
On the walk from the summit parking lot, Kagami Numa is the first pond you reach. The Megane Numa ponds lie just beyond it.
Hachimantai Nature Trail Circuit
Official length: about 5.0 km (Japan National Tourism Organization’s national park page). The trail starts at the Hachimantai Summit Rest House and passes the ponds before climbing Mount Gentamori and Mount Hachimantai.
Best Seasons to Visit
Spring (Late May to Early June)
It’s the only opportunity to see the legendary Dragon Eye effect. A melting icy lake stands in stark contrast to crisp air, hanging snow walls along the Aspite Line, and bright blue skies.
The Summer Months (July-August)
When the ice finally breaks up, the lake becomes a tranquil, clear volcanic lake, set amidst plentiful beech trees and dazzling wildflowers. Summer is a great time to travel leisurely.
Fall or Late September to October
The Hachimantai plateau is a dazzling array of red, gold, and deep orange in the fall. Fall foliage season is the best time to drive the Aspite Line for some of the best views of the mountains in northern Japan.
The Winter Months (November to April)
High mountain roads shut when there is a lot of snow. All across the plateau, it freezes, creating a snow-covered snowshoeing and backcountry skiing wonderland for the seasoned winter adventurer.
Planning to Travel in the North of Japan
Kagami Numa Lake offers a unique experience, a world phenomenon, great trails up the hill, and relaxing geothermal hot springs. With precise timing, the right equipment, and a healthy dose of common sense, your journey to the Dragon Eye should be a smooth, safe, and memorable experience.
How We Would Time a Dragon Eye Visit
| Question | What we would do | Why |
|---|---|---|
| When to go | Watch Akita Prefecture’s dated Dragon Eye updates for a week before travelling | The eye is visible for about two weeks from late May into mid-June, and the dates shift each year |
| Which day | Choose a weekday if you can | Traffic can back up on the Hachimantai Aspite Line in the peak weeks |
| Which walk | The 2.5 km summit loop, about 1 to 1.5 hours | It reaches Kagami Numa, Megane Numa and the lookout tower on a boardwalk |
| What to wear | Waterproof boots and light spikes | The path can still be snowy and icy in late spring |
We would not decide until the day before, because a few days either way changes what you see: come too early and the pond is a white snowfield, too late and the central island of snow has melted. We would also use the toilets at the Visitor Center or the foot of the mountain first, since the guide says the summit rest house is busy in peak weeks, and we would never step onto the thawing pond, as the official signs warn.
If you are building a northern Honshu trip, our Hakkoda Mountains guide and Hakkoda Ropeway guide cover the next prefecture over.
Kagami Numa FAQ
When can I see the Dragon Eye?
Usually for about two weeks between late May and mid-June. The exact timing changes every year with snowfall and weather, so check the dated updates on Akita Prefecture’s official Dragon Eye page before you travel.
How long is the walk to Kagami Numa?
About 15 to 20 minutes on foot from the summit parking lot at the Hachimantai Mountaintop Rest House. In the lingering-snow season the path can be snowy, so wear waterproof, non-slip footwear.
Is it safe to walk out onto the pond?
No. The official visitor sign warns that the pond can be dangerous while it thaws and asks visitors to keep away from the edge. Stay on the marked path and behind the ropes.
Are there toilets near the pond?
According to Akita Prefecture’s Dragon Eye page, the only toilet at the summit is in the summit rest house, and it gets busy in the peak weeks. It helps to use the facilities at the Visitor Center or at the foot of the mountain first.
Can I get there without a car?
Yes. Buses run from JR Morioka Station to the Hachimantai summit area in spring to autumn, taking about two hours. Buses from Tazawako run on limited days only, so check the operator’s current timetable.
Sources and Last Check
This guide is compiled from official and public-body information, not from a first-hand visit. We last checked these sources on October 9, 2026. Dates, bus timetables and opening schedules change, so confirm them with the operators before you go.
- Akita Prefecture: Hachimantai Dragon Eye information page
- Japan National Tourism Organization / Hachimantai DMO: Hachimantai Dragon Eye
- Ministry of Land, Infrastructure, Transport and Tourism: Hachimannuma Pond and the Hachimantai Summit sign text
- Japan National Tourism Organization: Mount Hachimantai Nature Trail
- Ministry of the Environment: Hachimantai Nature Observation Trail course
- Iwate Tourism: Hachimantai Aspite Line
