Drive north from central Shizuoka into the mountains, over one ridge after another, and after about two hours a long, narrow blue-green lake appears before you: this is Lake Ikawa, at the very top of the Oi River.
Lake Ikawa is a reservoir formed by Ikawa Dam, surrounded by the mountain forests on the edge of the Southern Alps, and in autumn the maples and mixed broadleaf woods on both shores turn from green to red, orange and yellow.
It is a long way from the city and not particularly easy to reach, yet you can take a free ferry to see the autumn leaves from the lake and walk along the shore on the tracks of an old railway, making it a rare hidden autumn-leaf spot in Shizuoka.
The questions people ask most when planning are: when are the autumn leaves at Lake Ikawa at their best? Do you need to book the ferry? How do you ride the Oigawa Railway Ikawa Line now that it requires reservations? And what should you watch out for if you drive up yourself?
This article draws on information published by the Japan Weather Association’s tenki.jp, the Shizuoka City Ikawa Branch Office and the Oigawa Railway to set out the viewing season, the must-see spots, the ferry timetable, access and itinerary planning all in one place.
If you are looking for an uncrowded autumn-leaf spot with lake views in the mountains of Shizuoka, you can use the itinerary suggestions at the end as they are.
Where Is Lake Ikawa? Getting to Know the Reservoir at the Top of the Oi River
Lake Ikawa is in Ikawa, Aoi Ward, Shizuoka City, Shizuoka Prefecture; it is a reservoir on the upper Oi River and belongs to the mountain area that Shizuoka City calls “Okushizu” (Oku-Shizuoka).
According to the Shizuoka City Ikawa Branch Office’s introduction, the Ikawa area is about 60 kilometres from central Shizuoka, about 2 hours by car, at an altitude of about 670 metres.
Temperatures in Ikawa are about 5 degrees lower than in the city, the changing seasons are very clear from the fresh greenery of spring to the autumn leaves of early winter, and in winter there are even days below minus 10 degrees.
At the southern end of the lake are Ikawa Dam and Ikawa Station, the terminus of the Oigawa Railway Ikawa Line, while upstream on the lakeshore lies Ikawa Honmura, the main settlement of Ikawa, and a ferry runs between the two.
Ikawa Dam and the Chubu Electric Power Ikawa Exhibition Hall
Ikawa Dam was completed in 1957 (Showa 32) and was the first hollow gravity dam in Japan, with a maximum output of 62,000 kilowatts and a total storage capacity of about 150 million tonnes at the time of completion.
The Chubu Electric Power Ikawa Exhibition Hall beside the dam is free to visit, and its exhibits explain how hydroelectric power works, the role of the dam and the relationship between nature and electricity; if you like, you can also pick up a dam card.
According to Shizuoka City’s Okushizu introduction to the exhibition hall, it is open from 9:00 to 16:00 and closed on Mondays (or the following day if Monday is a public holiday) and from December to February, but it does not close in May, August or November.
In other words, during the November autumn-leaf season you can visit the exhibition hall every day, and use it as a rest stop after seeing the dam while waiting for the ferry.
The Origins of the Ferry
The Lake Ikawa ferry has been running since 1958 (Showa 33); it was originally set up for residents who lost their transport links to the opposite shore because of the dam construction, and today visitors can ride it free of charge too.
Sitting in a small boat that local residents also use and watching the mountain colours on both shores is what sets Lake Ikawa apart most from other autumn-leaf spots.
How It Relates to Sumatakyo
Lake Ikawa and Sumatakyo are both in the Oku-Oi area of the Oi River basin, but Sumatakyo is on the Sumata River in Kawanehon Town, whereas Lake Ikawa is further north, on the main Oi River in Aoi Ward, Shizuoka City.
tenki.jp’s introduction mentions that there is also a “Yume no Tsuribashi” (suspension bridge of dreams) along the lakeside nature trail, which is a different bridge from the famous Yume no Tsuribashi at Sumatakyo, so do not mix them up when planning.
For the suspension bridge, queues and access at Sumatakyo, see our Sumatakyo autumn leaves guide; this article focuses on Lake Ikawa.
When Are the Autumn Leaves at Lake Ikawa at Their Best? Timing Your 2026 Visit
Different sources give slightly different timings for the autumn leaves at Lake Ikawa, so let us start by putting them side by side.
The Japan Weather Association’s tenki.jp autumn-leaf page for the Lake Ikawa area shows the usual peak as late October to mid-November, and its forecast peak for 2026 is likewise late October to mid-November.
The autumn-leaf website Walkerplus, on the other hand, says the leaves usually start to turn in mid-October, with the peak from late October to late November.
Shizuoka City Okushizu’s introduction to the Lake Ikawa autumn leaves puts the peak at roughly late October to early November, and notes that it shifts earlier or later depending on the weather.
Taking the three sources together, the viewing season at Lake Ikawa runs roughly from late October to mid-November, and the most recommended time is early November.
The Japan Weather Association’s 2026 Forecast for Tokai
The Japan Weather Association’s 2026 autumn-leaf peak forecast indicates that in eastern Japan (Kanto-Koshin, Hokuriku and Tokai) the peak will be around the usual time or later than usual.
The forecast explains that the first half of September was cool for a while, but temperatures have been above average since the second half of September and are expected to stay warmer than usual through November.
Lake Ikawa is higher than the city, but in a warm autumn the most beautiful period may still shift a few days later.
The Japan Weather Association plans to update the forecast three or four times on tenki.jp up to November, so the safest approach is to check the latest conditions again a week before you set off.
Which Trees Change Colour at Lake Ikawa?
tenki.jp lists maples, other maple species and lacquer trees as the trees that change colour, and Walkerplus also lists mixed broadleaf trees such as konara oak and sawtooth oak (kunugi).
The red of the lacquer trees is usually especially vivid, the maples turn red and orange, and the konara and sawtooth oaks take on yellowish-brown tones.
So the autumn leaves at Lake Ikawa are not a single sheet of red, but a mix of red, orange, yellow and brown set among the deep green of the cedar forests, which looks wonderfully layered from the lake.
What Will You See at Different Times?
If you come from mid- to late October, the mountaintops and the lacquer trees turn first while most of the trees by the lake are still green, giving an early-autumn scene of red among the green.
Early November is usually the main peak, when the slopes on both shores colour up together and the contrast between the blue-green water and the autumn leaves is at its strongest.
From mid-November onwards the trees higher up start to shed their leaves while some colour lingers on the lower slopes by the lake, and mornings and evenings in the mountains get much colder, so bring plenty of warm clothing.
Must-See Autumn-Leaf Spots at Lake Ikawa
Lake Ikawa is a long, narrow reservoir, and the main ways to enjoy the autumn leaves are by boat, by crossing the bridge and by walking along the lake, so they are set out below by location.
Seeing the Autumn Leaves from the Lake by Ferry
The first viewing point recommended by Walkerplus is the autumn leaves on both shores seen from the boat.
The regular Lake Ikawa ferry runs between Ikawa Dam and Ikawa Honmura, taking about 15 minutes each way, and as the boat moves the slopes on both shores glide slowly past you.
On fine days the water is blue-green, and tenki.jp also points out the strong contrast between the emerald green of the lake and the red of the autumn leaves.
If you want to spend longer on the lake, you can book a sightseeing boat that departs from Ikawa Honmura and loops round to the Ikawa Ohashi Bridge, taking about 40 minutes.
Ikawa Ohashi Bridge
The Ikawa Ohashi Bridge is a suspension bridge across Lake Ikawa, 258 metres long and about 2.5 metres wide; vehicles with a gross weight of up to 2 tonnes may cross, so ordinary cars can drive over it.
According to Shizuoka City’s Okushizu introduction, from the bridge you can look out over Lake Ikawa and Mt Kamikochi in the Southern Alps, and the deck is about 60 metres above the water.
Walkerplus also lists the lake view from the Ikawa Ohashi Bridge as a recommended spot; in the autumn-leaf season, standing on the bridge and looking upstream and downstream, you see coloured slopes on both sides.
The deck is only about 2.5 metres wide, and signs on site ask drivers to cross one car at a time and slowly, and to give way to pedestrians.
Lake Ikawa Lakeside Trail (Haisen Komichi)
The Lake Ikawa Lakeside Trail, nicknamed “Haisen Komichi” (disused railway lane), is a walking trail made from the abandoned railway that led to the former Dodaira Station, a materials-handling station used during the construction of Ikawa Dam, with the tracks left in place.
According to Shizuoka City Okushizu’s introduction to Haisen Komichi, the trail opened in October 2013 (Heisei 25), its entrance is behind the Chubu Electric Power Ikawa Exhibition Hall, and it is free to use.
You can walk right on the rails, there is a short tunnel along the way, and benches are placed along the route so you can sit down and take in the lake view at leisure.
Walkerplus also lists the contrast between the lake and the autumn leaves seen from Haisen Komichi as a recommended spot; this is a place where you can enjoy the lake scenery properly without taking the boat.
The trail follows the hillside along the shore and is narrow in places, so wear comfortable shoes and watch out for slippery surfaces after rain.
Ikawa Daibutsu
The Ikawa Daibutsu stands around the Matsuyama area of Ikawa; it was built over four years by Sato Heiichiro, a dentist at a local clinic, in gratitude for sixty years of good health.
The Buddha is 11 metres tall, its eye-opening ceremony was held on 1 November 1980 (Showa 55), and annual festivals are held every April and October.
Alongside the autumn leaves by the lake, stopping off to see this great Buddha built from one person’s vow is also a good way to get to know Ikawa’s local stories.
How to Ride the Lake Ikawa Ferry: Timetable and Tips
The Lake Ikawa ferry is run by Shizuoka City and all routes are free; below are the times published on the Lake Ikawa ferry information page, which as of October 2026 still follows the timetable revised in June 2024.
| Route | Details | Times and notes |
|---|---|---|
| Regular service (Dam route) | Ikawa Dam to Ikawa Honmura, about 15 minutes each way | From Honmura 10:55, 12:10, 13:20, 14:30; from the dam 11:35, 12:45, 13:55, 15:05 |
| Sightseeing boat (reservation only) | Departs Ikawa Honmura, about 40-minute loop round the Ikawa Ohashi Bridge | 10:00, 11:00, 13:00, 14:00; does not sail without a reservation |
| Miyamukai route | Ikawa Honmura to Miyamukai, about 10 minutes each way | Runs on request at any time |
The regular service operates from 27 April to 22 December, and from 2 December to 22 December it runs only on Saturdays and Sundays.
The sightseeing boat can be booked from three weeks before the day of sailing, through the “Okushizu Batta” booking website or by phone to the ferry waiting room.
What to Know Before Taking the Ferry
Each boat holds 20 people and the autumn-leaf season is very busy, so the regular service may be full and you may not manage to ride both ways; the city specifically warns about this.
The ferry is suspended in heavy rain, strong winds or when the water level is too low, and the lake music festival in September 2026 was cancelled because the water level of Lake Ikawa had dropped markedly.
On the day, you can phone the Lake Ikawa ferry waiting room or check the X account run by the waiting room to confirm whether the ferry is running.
The waiting room is at Ikawa Honmura; there is none on the dam side, and in front of the dam-side landing there is parking space for only about 5 cars.
When riding the Akaishi Maru, stay seated and wear a life jacket while the boat is moving, and take particular care if you have children with you.
Opening Hours and Costs
Lake Ikawa itself has no admission charge, and the main cost is transport; below is the information as of October 2026.
| Item | Details |
|---|---|
| Lake Ikawa area | Open all year, free |
| Lake Ikawa ferry | All routes free |
| Chubu Electric Power Ikawa Exhibition Hall | 9:00 to 16:00, free; closed on Mondays and from December to February, open every day in November |
| Lake Ikawa Lakeside Trail (Haisen Komichi) | Free |
| Oigawa Railway Ikawa Line | One-way ride plan: adults 3,500 yen, children 1,750 yen (same price for any section, advance reservation required) |
The Ikawa Line prices and reservation rules come from the Oigawa Railway’s Ikawa Line page; package plans with a bento, hot spring and so on are priced separately.
How to Get to Lake Ikawa: Train, Bus and Car
Lake Ikawa is deep in the mountains and takes a fair amount of time to reach whether you go by public transport or by car, so each option is explained below.
Oigawa Railway plus the Ikawa Line (Minami Alps Abt Line)
By rail, first change at Kanaya Station on the JR Tokaido Line to the Oigawa Railway Main Line to Senzu Station, then change to the Ikawa Line and ride to the terminus at Ikawa Station.
Services on the Oigawa Railway Main Line are suspended between Kawane-Onsen-Sasamado and Senzu, so to reach Senzu you change at Ieyama Station to a Kawanehon Town bus; check the service information on the Oigawa Railway website before you set off.
The Ikawa Line from Senzu to Ikawa is 25.5 kilometres long and the little red train takes about 2 hours, passing Okuoikojo Station and the only Abt rack railway section in Japan along the way.
According to the Oigawa Railway’s Ikawa Line page, from 1 July 2026 all Ikawa Line trains require advance reservations, and the basic one-way plan costs 3,500 yen for adults whichever station you ride to.
You reserve a specific train but seats are unreserved, and if there is space you can also buy on the day through the booking website, at a station ticket window or on board, but booking early is recommended in the autumn-leaf season.
Shizuoka City’s introduction says that from Ikawa Station it is about a 10-minute walk towards the Ikawa Hydropower Management Office to reach the dam-side ferry landing.
From Ikawa Station to Ikawa Honmura, you can walk the trail in about 90 minutes or take the community-run bus to the “Tosenba” (ferry landing) stop.
By Bus: Shizutetsu Bus plus the Ikawa Area Community-Run Bus
From central Shizuoka by bus, first take a Shizutetsu JustLine Abe Line service bound for “Yokosawa”, then at “Yokosawa” change to the Ikawa area community-run bus “Teshaman-kun”.
According to Shizuoka City’s introduction to the Ikawa area community-run bus, the bus runs every day, but the vehicle is a single van with only 9 seats.
When it is full, Ikawa area residents are given priority, it cannot be booked, and the fare is paid in advance in cash only, with no transport IC cards or credit cards accepted.
Large luggage that does not fit within the seating space cannot be taken on board, so travellers with suitcases should take particular note.
By Car: Narrow Mountain Roads, So Check Road Information Before You Go
If you are driving, Walkerplus’s information says it takes about 90 minutes from Shin-Shizuoka IC on the Shin-Tomei Expressway, or about 120 minutes from Shizuoka IC on the Tomei Expressway.
From the Shin-Shizuoka IC direction, you can take Prefectural Road 27, via Prefectural Road 189 (Yokosawa) and Prefectural Road 60 (Fujimi Pass), or via Kuchisakamoto on Prefectural Road 27 and then Prefectural Road 60.
From the Shin-Tomei Shizuoka Smart IC direction, take National Route 362, then Prefectural Road 77 (Senzu in Kawanehon Town and Sessokyo) and the Kanzo municipal road into Ikawa.
All of these roads have narrow sections where passing is difficult and stretches prone to rockfalls, and Shizuoka City also advises checking the latest conditions on the road restriction information website “Shizumichi info” before you set off.
The Kanzo municipal road was fully closed after a slope collapse in September 2025, and according to Shizuoka City’s notice on traffic restrictions on the Kanzo road, since 25 December 2025 it has instead been closed at night from 18:30 to 6:30 the next morning.
If you are taking the ferry, you can park in the upper car park of the Shizuoka City Hall Ikawa Branch Office, about a 5-minute walk from the ferry landing.
The mountain roads have no street lights at night and many bends, so we recommend coming down before dark and not leaving your return too late.
Private Car: Leave the Mountain Roads to a Driver Who Knows Them
The mountain roads to Lake Ikawa are narrow and winding, so drivers need a fair amount of mountain-road experience, while the buses are limited by seating capacity and timetables.
If you are travelling with older relatives or children, have lots of luggage, or want to link Lake Ikawa with other Oku-Oi spots in one day, a private car saves you a great deal of effort changing transport and driving.
Suggested Time and Itinerary
If you only take the ferry there and back and walk around the dam, about 2 hours is enough, and with a walk along Haisen Komichi, the Ikawa Ohashi Bridge and the Ikawa Daibutsu, allow half a day for a more relaxed visit.
Because the drive takes about two hours each way, Lake Ikawa is basically a full-day trip if you set off from central Shizuoka.
| Time | Plan | Highlights |
|---|---|---|
| 8:00 | Leave central Shizuoka | Take Prefectural Road 27 towards Ikawa |
| 10:30 | Arrive at Ikawa Honmura | Park in the upper car park of the Ikawa Branch Office |
| 10:55 | Regular ferry to Ikawa Dam | Autumn leaves from the lake, about 15 minutes |
| 11:15 | Ikawa Dam and the Ikawa Exhibition Hall | The dam, the exhibition hall and views from the dam |
| 12:00 | Haisen Komichi walk and lunch | Lakeside trail and a rest on the benches |
| 13:55 | Ferry back to Ikawa Honmura | One more look at the lake on the way back |
| 14:30 | Ikawa Ohashi Bridge and Ikawa Daibutsu | The lake and mountains from the bridge |
| 15:30 | Head down the mountain | Leave the mountain roads before dark |
The ferry may be full in the autumn-leaf season, so the sailings in the itinerary are only a guide; if you cannot get on, you can drive to the dam side instead, or spend the time on Haisen Komichi.
Combining with Nearby Spots
If you are taking the Ikawa Line, you can get off on the way at Okuoikojo Station; the Oigawa Railway says that a walk of about 20 minutes from the station across the Oku-Oi Rainbow Bridge brings you to a viewpoint overlooking the station and Lake Sesso.
Sumatakyo, also in Oku-Oi but in Kawanehon Town, is another popular autumn-leaf spot in the Oi River basin, but it lies in a different direction from Lake Ikawa, so if you want to include both in one trip it is best to split them over two days.
Umegashima Onsen, also in the mountains of Aoi Ward, Shizuoka City, is well worth visiting in autumn too, so you could spend a day at each and stay in the mountains to enjoy the hot springs.
Lake Ikawa Autumn Leaves FAQ
Q1: When are the autumn leaves at Lake Ikawa at their best?
Usually from about late October to mid-November, with early November the most recommended time.
For 2026 the Japan Weather Association forecasts that the Tokai autumn leaves will peak around the usual time or slightly later, so please check the latest conditions on tenki.jp again before you set off.
Q2: Does the ferry cost anything? Do I need to book?
All Lake Ikawa ferry routes are free, and the regular service between the dam and Honmura does not need booking, but it holds 20 people and may be full in the autumn-leaf season.
The sightseeing boat that loops round to the Ikawa Ohashi Bridge is reservation only and does not sail without bookings; reservations open three weeks in advance.
Q3: Can I just buy a ticket and board the Ikawa Line now?
From 1 July 2026 all Ikawa Line trains require advance reservations, and you can only buy on the day through the booking website, at a station ticket window or on board if there is space.
Weekends in the autumn-leaf season are very popular, so we recommend booking your train on the Oigawa Railway booking website before you set off.
Q4: Is Lake Ikawa suitable for driving to?
You can drive, but the mountain roads are narrow with many bends, some sections carry a risk of rockfalls, and the Kanzo municipal road is also closed at night.
If you are not familiar with Japanese mountain roads, consider a private car, or take the train and bus instead.
Q5: Can I visit Lake Ikawa and Sumatakyo on the same day?
Both are in the Oi River basin, but the routes are different: Lake Ikawa is reached from central Shizuoka or the Ikawa Line terminus, while Sumatakyo is reached from Senzu towards the Sumata River.
If you want to see both properly, we suggest splitting them over two days and staying at a hot spring in Oku-Oi in between.
Final Thoughts: A Free Autumn-Leaf Ferry Ride at the Top of the Oi River
What makes Lake Ikawa special is that it is far from the crowds, you can see the autumn leaves from an everyday ferry on the blue-green lake, and you can walk along the shore on an old railway line.
When planning, remember three things: the peak is roughly late October to mid-November (early November is the most recommended), the ferry holds only 20 people and is suspended due to weather or water levels, and the Ikawa Line now requires advance reservations.
With these points sorted, Lake Ikawa fits nicely into an autumn trip to Shizuoka as a full-day getaway to a mountain lake.
Further Reading
- Sumatakyo, Shizuoka Autumn Leaves Guide: Yume no Tsuribashi, Queues and Oigawa Railway Access
- Umegashima Onsen, Shizuoka Autumn Leaves Guide: Best Time, Akamizu Falls Illumination and Access
- Hakuho Keikoku, Southern Alps, Yamanashi Autumn Leaves Guide: Peak, Forest Road Bus and Access
- Oguni Shrine, Shizuoka Autumn Leaves Guide: Best Time and Momiji Matsuri Illumination
Lake Ikawa is about two hours of mountain road from central Shizuoka and the bus seats only 9, so if you are travelling with older relatives or children, have lots of luggage, or want to link Lake Ikawa with other Oku-Oi spots in one day, getting around is often the most demanding part.
If you need a car or transfers in Japan, give SEN Concierge your dates, number of people, amount of luggage and the legs you plan to travel, and we will arrange a Toyota Alphard (1–4 people) or a HiAce (5 or more) depending on your group and luggage.
Quotes include tax, fuel, expressway tolls and the night surcharge, and you can pay online by card, and you can check vehicle types and rates first on our Japan airport transfer and private charter price list.
By completing an inquiry and confirming a booking, you are deemed to have read and agreed to SEN Concierge’s “Refund, Cancellation and Rescheduling Policy“. Please review it again before booking.