Lake Yu — Yunoko (湯の湖) — sits at 1,500 metres above sea level in the Yumoto Onsen area, the furthest and highest point on the Tobu Bus route from Nikko. It is a small, circular alpine lake surrounded by deciduous forest, with Nantai Mountain visible to the south and the Shirane Mountain range set back to the northwest. The lake loop is about one hour of easy walking, following a trail that combines lakeside path and occasional road sections. Tame ducks patrol the shore and approach hikers looking for food. Autumn foliage here is among the earliest in the Nikko area, arriving two to three weeks before the shrines below. For those finishing a Senjogahara hike at Yumoto Onsen, the Lake Yu loop is the perfect complement — an extra hour of gentle walking before the bus home, or a hot-spring bath at the Yumoto onsen inns.
👞 Trail at a Glance
| 📏 Distance | ~3 km loop around the lake |
| ⏱ Duration | 1 hour |
| 💪 Difficulty | Easy — Class 1 (flat lakeside walk) |
| 📍 Trailhead | Yumoto Onsen bus terminal, Lake Yu shore |
| ⛰ Elevation | ~1,500 m above sea level |
| 🔄 Trail Type | Loop |
| 🌸 Best Season | May – November (koyo arrives late September – early October) |
| 🚌 Bus Access | Tobu Bus to Yumoto Onsen (end of line) — All Nikko Pass or Yumoto Onsen Pass |
| 🌿 National Park | Yes — Nikko National Park |
| 🛶 Boats | Rental rowing boats available on the lake |
🏠 Stay at Earth Hostel Nikko Riverhouse — free shuttle to Nikko Station. Lake Yu is 60–75 minutes by bus. Pairs perfectly with Senjogahara.
Why Visit Lake Yu?
Lake Yu is the natural endpoint for one of Nikko’s most popular routes: hiking the Senjogahara boardwalk trail from Ryuzu Waterfall northward. After 2.5–5 hours on the Senjogahara plateau, arriving at Yumoto Onsen and adding a gentle loop around Lake Yu turns a great hike into a complete day. The lake offers everything the plateau doesn’t: stillness, shade, a close-up view of alpine water, and the reward of a hot-spring bath at one of the Yumoto inns when you return to the terminal.
The lake is also one of the few places in Nikko where autumn foliage reliably arrives in late September and early October — weeks before the shrine area in the valley. If you time your visit right, you can see koyo at Lake Yu while the lower elevations are still fully green, then return for a second visit when autumn colour has worked its way down to Senjogahara and Lake Chuzenji in October.
It is also the only point in Nikko from which Shirane Mountain (the highest peak in the Kanto region) can be accessed by trail. The Shirane trailhead sits just north of the Yumoto Camping area, several hundred metres from the lake.
Getting to Lake Yu
By bus: Take the Tobu Bus from Tobu Nikko or JR Nikko station all the way to Yumoto Onsen — the last and furthest stop on the route. Journey time: approximately 60–75 minutes from Nikko station. You will need the Yumoto Onsen Pass or the All Nikko Pass. This is the furthest point covered by the All Nikko Pass purchased at Asakusa station in Tokyo, making it a natural end-of-line destination for travellers coming from the capital.
On foot from Senjogahara: Most travellers reach Lake Yu by hiking north from Ryuzu Waterfall along the Senjogahara boardwalk trail. Arriving at Yumoto Onsen after the full trail puts you at the lake’s southern shore. The Lake Yu loop continues from there.
From Earth Hostel: Free morning shuttle to Nikko Station, then the Yumoto Onsen bus. Lake Yu makes a great standalone day when combined with an early Senjogahara start. Allow a full day.
The Lake Yu Trail
The trail loops around Lake Yu in approximately one hour. The path follows the lake shore closely, mixing quiet lakeside trail with brief road sections. The character of the walk is gentle and unhurried — this is not a strenuous hike but a nature walk with very good views.
Ducks: The ducks at Lake Yu are famously tame. They approach hikers along the shore looking for food offerings. This is charming and somewhat incongruous with the wild mountain setting. Bring bread if you want a genuinely memorable wildlife moment.
Quiet pockets: Despite the short loop distance, the trail has several sections that feel genuinely remote — fallen trees, thick moss, open meadows, and sheltered alcoves where the sound of the lake water is the only thing audible. The contrast with the busier sections near the bus terminal is marked.
Nantai Mountain views: Clear views of Nantai Mountain appear across the lake from several points on the trail. From this angle and elevation, the mountain’s volcanic cone looks different from the views at Lake Chuzenji below — more immediate and imposing.
Ryuzu Waterfall (top): From the southern shore of Lake Yu, the very top of Ryuzu Waterfall is visible — the point where the lake’s outlet begins its cascade down to Lake Chuzenji. This perspective, looking down the outlet from above, is one that most visitors to Ryuzu never see.
Rental boats: Rowing boats are available to hire on the lake in season. Getting onto the water gives a completely different perspective of the surrounding mountains and forest.
Trail Photos
Lake Yu — a small, beautiful alpine lake at 1,500 m. Much quieter than Lake Chuzenji below.
Lake Yu in summer — deep green forest reflected on still water.
In autumn, Lake Yu turns extraordinary. Koyo arrives here in late September — among the earliest colour in Nikko.
Autumn leaves reflected on Lake Yu. Late September to mid-October is the prime window at this elevation.
Rental rowing boats available on the lake in season — one of the few places in Nikko National Park to get out on the water.
The lakeside hiking path with Nantai Mountain visible across the water — a distinctive view of the volcano from the north.
The tame ducks of Lake Yu — they approach hikers along the shore. Bread is warmly received.
The top of Ryuzu Waterfall, visible from Lake Yu’s southern shore — the point where the lake’s outlet begins its cascade down to Lake Chuzenji.
A meadow section on the trail — one of the quiet pockets that appear between the more open lakeside sections.
Combine With: Senjogahara + Lake Yu Full Day
The classic Nikko full day: take the first morning bus to Ryuzu Waterfall. Hike the Senjogahara boardwalk trail north to Yumoto Onsen (2.5–5 hours depending on pace). Add the Lake Yu loop (1 hour). Visit the Yumoto Onsen hot-spring baths. Take the late afternoon bus back to Nikko. This is one of the best full days available in Nikko National Park, requires only one bus pass, and can be done comfortably from Earth Hostel using the free morning shuttle.
Best Season
| Season | Conditions | Notes |
|---|---|---|
| May – June | Fresh spring green; quiet; clear lake | Very few visitors. Ideal for the peaceful atmosphere the lake offers. |
| July – August | Summer green; 5–8°C cooler than Nikko town | Good season for combining with Senjogahara. Boat hire available. |
| Late Sept – mid Oct | Peak koyo — among the earliest in Nikko | Outstanding. Come here 2–3 weeks before the valley shrine area for uncrowded autumn colour. |
| November | Late autumn; buses reduce; possible snow | Check bus schedules before visiting. Snow hiking is possible in good conditions. |
| December – April | Lake may freeze; bus service reduced or suspended | Winter visits require checking bus schedules carefully. The frozen lake is beautiful but access is uncertain. |
Frequently Asked Questions
How do I get to Lake Yu from Nikko station?
Take the Tobu Bus all the way to Yumoto Onsen — the last stop, approximately 60–75 minutes from Tobu Nikko or JR Nikko station. Buy the Yumoto Onsen Pass or All Nikko Pass before departing. The lake is a short walk from the bus terminal.
Is Lake Yu the same as Yunoko?
Yes — Lake Yu, Yunoko, and Yumoto Lake all refer to the same body of water. “Yu” means hot water in Japanese, referencing the nearby hot spring (onsen). “Ko” means lake.
Can I see autumn foliage at Lake Yu?
Yes — and it arrives earlier here than anywhere else in Nikko. At 1,500 m elevation, koyo typically peaks at Lake Yu in late September to early October, two to three weeks ahead of the shrine district at 600 m. This makes it an excellent early-autumn destination before the main Nikko koyo crowds arrive.
Is Shirane Mountain accessible from Lake Yu?
Yes — the Shirane Mountain trailhead is at the Yumoto Camping area, several hundred metres north of the lake. Read our Shirane Mountain guide for the full two-day expedition details.
Are there hot springs at Yumoto Onsen?
Yes — Yumoto Onsen has several traditional ryokan (hot-spring inns) around the lake and village area. Most allow day-use bathing (higaeri nyuyoku) for a fee. After a full Senjogahara + Lake Yu day, soaking here before the bus home is the ideal way to finish.
Visit Lake Yu from Earth Hostel
Lake Yu is best experienced as part of a longer Oku-Nikko day from Earth Hostel. Our free morning shuttle gets you to Nikko Station for the first bus, and we can advise on whether to combine it with Senjogahara, Yutaki Falls, or a Shirane expedition. See all hiking trails in Nikko ›
Last updated: April 2026. Bus schedules to Yumoto Onsen are seasonal — verify before departing. Boat hire availability varies by season and operator.
