1
History and origin of Iroha-zaka

Iroha-zaka" is a part of the national highway connecting the city of Nikko and Lake Chuzenji.
There are two slopes, "Daini Irohazaka" (uphill) and "Daiichi Irohazaka" (downhill), each of which is a one-way street.
There are 48 curves on the First and Second Iroha Slopes, and each curve has a 48-syllable "iroha" sound, hence the name "Iroha Slope. The uphill "Dai-Iroha-zaka" has 20 letters from "i" to "ne", and the downhill "Dai-Iroha-zaka" has 28 letters from "na" to "n", and signs are placed at each curve.

The history of "Iroha-zaka" is related to the mountain worship of Nantai-san (Mt. Nantai) since the Nara period (710-794).
Nantai, so women and oxen and horses were prohibited from entering the path until the early Meiji period (1868-1912). In the Showa period (1926-1989), a road connecting Mt. Nantai and downtown Nikko was developed and improved, and it is now known as Iroha Slope.

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Highlights of Iroha-zaka slope in autumn leaves

The best season to visit Iroha-zaka is the season of autumn leaves.
The autumn foliage in Oku-Nikko usually begins in late September near the Ryuzu Falls (1,350 m) and descends to the city of Nikko over a period of about two months.
The best time to enjoy the vivid autumn leaves at "Iroha-zaka" located on the way down is usually from mid to late October.

Autumn leaves on the Iroha slope show different faces depending on the elevation.

The best time to enjoy the brilliant autumn leaves along "Iroha-zaka" is usually from mid to late October. The altitude of "Iroha-zaka" varies from 800 m at Umagaeshi at the foot of the slope to 1,260 m at Lake Chuzenji, so the season of autumn leaves differs depending on the altitude.
The difference in temperature between day and night and the difference in elevation causes the leaves to change color beautifully, and the tints of the leaves vary, so no matter how many times you visit during the fall foliage season, you can enjoy a different look each time you come.

The autumn foliage from Akechidaira is spectacular.

Akechidaira, located near the end of the "Daini-Iroha slope," has a rest area and a ropeway that goes to the Akechidaira Observation Deck.
From the Akechidaira Observation Deck, you can enjoy a panoramic view of Lake Chuzenji and Kegon Falls, which is truly a superb view of the autumn leaves.
Akechidaira can only be reached from the uphill "Daini-Iroha-zaka" slope, so be careful not to miss the entrance after the "Ne" curve.

Kinds of autumn leaves you can enjoy at Iroha-zaka

On Iroha-zaka, you can enjoy the autumn leaves of maple, Japanese maple, azalea, and katsura.

Japanese maple (Acer palmatum)

The fresh green foliage is also beautiful, and the red and yellow leaves of these trees are well-known for their autumn colors, which are also abundant on Iroha-zaka.

Nanakamado (Japanese maple)

Nanakamado, which bears small red berries, has leaves that turn "fiery red" during the autumn foliage season, creating a vivid contrast with the blue autumn sky.

azalea

The leaves turn almost orange-red, and the gradation of the bright red nanakamado makes for a beautiful sight.

Japanese Judas tree

During the foliage season, the leaves turn yellow.
Depending on the time of year, yellow and green leaves are still mixed together, and the colors of the maple, nanakamado, and azalea create an exquisite natural beauty that is pleasing to the eye.

Although we have introduced the typical types of trees that change their leaves to autumn colors, many trees are getting ready to change their colors at "Iroha-zaka", which offers a spectacular view of autumn leaves at different elevations.

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Direction and traffic jam information by car

Direction to "Iroha-zaka" usually takes about 2.5 hours from central Direction by car, and it takes about 15 minutes by car from the Kiyotaki IC of Nikko Utsunomiya Expressway.
The 9.5-km uphill "Daini-Iroha-zaka" usually takes 20 minutes, but during the autumn foliage season, it takes 2 to 3 hours, so be sure to check traffic congestion information frequently.

How to avoid heavy traffic on "Iroha-zaka" slope even on weekdays

Even on weekdays, the area is crowded with foliage tour buses, so early morning travel is recommended to avoid traffic jams.
Also, plan your trip so that you can start climbing "Iroha slope" by 7:00 a.m. on weekdays, and calculate the time to leave home.
On the way back, it is recommended to get off the "Iroha slope" by 3:00 p.m. at the latest to avoid getting caught in traffic jams.

Be prepared for heavy traffic on weekends and consecutive holidays.

According to the traffic jam forecast information, the expected time of traffic jam on weekends during the autumn foliage season is from 7:00 to 8:00 a.m. on the uphill side of "Iroha-zaka" and from 3:00 to 7:00 p.m. on the downhill side.
It is no exaggeration to say that if you get stuck in a traffic jam, you will not be able to "move.
To avoid traffic jams, it is recommended to go up "Iroha slope" at 6:00 a.m. and go down before 2:00 p.m.
Also, check the schedule of events in Nikko to avoid further traffic congestion, and plan your trip accordingly.

4
Direction by public transportation

　Buses bound for Chuzenji-ko Hot Spring or Yumoto Hot Spring leave from JR Nikko Station or Tobu Nikko Station on the Tobu Railway, and usually take about 40 minutes to reach Akechidaira.
If you drive along "Iroha-zaka" during the autumn foliage season, you will have to worry about traffic jams and parking, and the driver will not have time to enjoy the autumn foliage.
Please consider using public transportation as a way to enjoy the autumn foliage in a relaxed atmosphere.

The autumn foliage along "Iroha-zaka," which has been selected as one of the 100 best roads in Japan, is spectacular. Gather information and be prepared.
Enjoy the wonderful scenery.