Irohazaka is the mountain road connecting the town of Nikko to the Chuzenji-ko highlands, made up of 48 hairpin curves split across two one-way roads, one for the ascent and one for the descent, each curve traditionally named after a character of the old Japanese iroha syllabary. It was built to climb roughly 440 meters in elevation over a short distance to reach the plateau where Lake Chuzenji and Kegon Falls sit. The road itself is a scenic drive rather than a destination with a gate or ticket, valued for the forest and valley views on the way up.
Irohazaka Winding Road is a mountain pass on National Route 120 connecting central Nikko City to Chuzenji Onsen and Lake Chuzenji in Tochigi, built as two separate one-way roads: a 28-curve descending route and a 20-curve ascending route, each named after a character of the traditional Japanese iroha syllabary posted at every bend. The road climbs roughly 440 meters through dense forest, and drivers or bus passengers experience a continuous sequence of hairpin turns framed by beech, oak, and maple trees. The most common way to experience it is by car heading up toward Chuzenji Onsen and Lake Chuzenji, or by the Tobu bus that runs the same route; the drive takes about 30 to 45 minutes one-way depending on traffic. Mid-to-late October is peak season, when the 48 combined curves cut through a dense band of red and orange autumn foliage considered one of the Kanto region's best foliage drives, though this also brings heavy weekend traffic and long queues at scenic pull-offs like the Akechidaira viewpoint partway up the route. Traveling on a weekday morning or via bus avoids much of the congestion.
| Admission | Free |
|---|---|
| Hours | Open 24 hours |
| Typical visit | 30–45 minutes by car or bus (one-way) |
| Best time | Mid-to-late October for the 48-curve descent through peak autumn colour; avoid weekend afternoons in foliage season due to heavy traffic |
| Getting there | By car via Route 120 from central Nikko; or Tobu bus toward Chuzenji Onsen/Yumoto Onsen (40 min through the pass, ¥1,250 / ~$7.86) |
| Address | National Route 120, Nikko, Tochigi |
Location
National Route 120, Nikko, Tochigi
36.7295, 139.5195 View on map
Highlights
- 48 combined hairpin curves each marked with an iroha syllabary character
- Separate one-way ascending and descending routes through the forest
- Akechidaira viewpoint partway up the pass with ropeway access to a panoramic overlook
- Peak autumn foliage corridor connecting Nikko City to Lake Chuzenji
Tips for visiting
- Avoid weekend afternoons in October and November when foliage traffic backs up for hours
- Take the Tobu bus instead of driving to skip parking and traffic stress during peak season
- Stop at the Akechidaira viewpoint partway up for a wider panorama than the road itself offers
- Fill up on fuel before starting the drive, as services are limited along the pass
When to visit
Mid-to-late October brings peak autumn colour along the 48-curve route; weekday travel avoids the heavy weekend traffic common in foliage season.
Accessibility
As a driving and bus route rather than a walking attraction, the road itself has no pedestrian accessibility features; bus passengers with mobility needs should confirm boarding assistance with the operator in advance.
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Frequently asked questions
How long does it take to drive Irohazaka Winding Road?
The one-way drive through the pass takes about 30 to 45 minutes depending on traffic conditions.
Is Irohazaka worth it for kids?
Children often enjoy counting the numbered curves, though the winding drive can cause motion sickness for some, so breaks are worth planning.
Is photography allowed along Irohazaka?
Photography is allowed at designated pull-offs and viewpoints such as Akechidaira, though stopping directly on the curving road itself is unsafe and discouraged.