Irohazaka

Irohazaka is a scenic mountain road that connects the city of Nikko with Lake Chuzenji and Okunikko. It consists of the first Irohazaka, which is used only for downhill traffic, and the second Irohazaka, which is used only for uphill traffic. The 48 hairpin turns across both roads were named after the 48 Japanese syllables of the “Iroha” poem. Each curve is marked with signs for “i,” “ro,” “ha,” and so on, and the elevation difference is about 440 meters. The total length of the two roads is approximately 15.8 km, and it is one of Nikko’s signature driving routes, also selected as one of Japan’s 100 Best Roads.
• One-way traffic: Second Irohazaka = uphill / First Irohazaka = downhill
• Curve markers: Second Irohazaka has 20 markers from “i” to “ne”; First Irohazaka has 28 markers from “na” to “n”
• Driving time (normal conditions): About 20 minutes on the second Irohazaka (may vary depending on the season and traffic conditions)

Scenic Spots
Akechidaira
A popular viewpoint along the uphill-only second Irohazaka. A few minutes up from the parking area by the Akechidaira Ropeway, the observatory offers a panoramic view of Lake Chuzenji, Mount Nantai, and Kegon Falls. Since it can only be accessed from the uphill direction, be careful not to miss it as you pass by.
Kurokamidaira
Located about midway along the second Irohazaka (uphill), this viewpoint opens out toward the Kanto Plain. On clear days, the distant scenery is beautiful, making it an ideal place for a short break during your drive.

Seasonal Highlights
• Spring to early summer: Fresh greenery changes with elevation, offering a refreshing landscape.
• Summer: Driving through the tunnel of deep green is cool and comfortable, making it a great escape from the heat.
• Autumn (fall foliage): Known as one of Nikko’s premier spots for autumn leaves, with peak colors usually from mid- to late October. Because the timing of the foliage changes with elevation, you can enjoy a wide variety of colors over an extended period (at higher elevations, the best viewing may continue into early November).
o Main tree species: maple, rowan, azalea, katsura, and others. The contrast of red, yellow, and orange is especially vivid.

Traffic Congestion and Crowding Countermeasures
During the autumn foliage season and long holiday periods, traffic jams of two to three hours or more can occur (in some cases, up to six hours in the past).
The following measures are recommended:
• Avoid peak hours: For uphill traffic, early morning (until around 7 a.m.) is ideal; for downhill traffic, early afternoon (around 2 p.m.) is best.
• Sightsee during off-peak times: In line with the “Challenge Irohazaka Traffic Jam Relief Project,” visitors are encouraged to avoid sightseeing on weekends and holidays between 9:00 a.m. and 3:00 p.m.
• Use public transportation: Consider switching from a private car to shuttle ropeway or bus services, including additional and temporary services.

Driving and Safety Tips
• Because the road has many steep grades and sharp curves, drive at a moderate speed and make frequent use of engine braking.
• Sightseeing and photography should be done in designated areas such as Akechidaira; avoid stopping on the road.
• Wet fallen leaves, snow, and icy conditions can make the road slippery, so winter tires and chains are necessary in winter.

History and Origin
The name Irohazaka comes from the 48 curves being likened to the 48 Japanese syllables of the “Iroha” poem.
In the Nara period, it was used as a pilgrimage route for mountain worship centered on Mount Nantai as a sacred object. Until the Meiji period, Okunikko was considered sacred ground, and there were times when women, cattle, and horses were prohibited from entering. After improvements in the Showa era, it became the current automobile road, and today it is beloved by many as a route symbolic of sightseeing in Nikko.

Irohazaka is a dynamic mountain road shaped by a 440-meter elevation difference and 48 curves. With the grand panorama from Akechidaira and the natural beauty that changes with the seasons, it is widely known throughout Japan as one of Nikko’s most spectacular driving routes. Autumn in particular is expected to be crowded, so please enjoy your visit with plenty of time by using off-peak hours and public transportation.