Iroha-zaka is a pair of famous winding roads located in the mountains of Tochigi Prefecture, Japan. It’s the main access to connect the lower elevations around central Nikko to the higher elevations of the mountainous Okunikko region.
This pair of asphalted roads it’s a 1-way switchback mountain road (2 separate roads; up and down). It’s necessary to use the Second Iroha-zaka to go up, and use the First Iroha-zaka to come down.
Each corner has a letter of ancient Japanese alphabet, and you will see it in alphabetical order. The alphabetical order starts from I-ro-ha, while modern alphabet starts from a-i-u. This road used to be for ascetics in the past. Iroha-Zaka ascends more than 1,300 feet (396 m). This road plays a significant role in Japanese history: The route was popular with Buddhist pilgrims on their way to Lake Chuzenji, which is at the top of the forested hill that this road climbs.
"Iroha" are the first three of 48 syllables of the formerly used Japanese alphabet (which is now known as "aiueo"), and "zaka" means "slope" - the Irohazaka Winding Roads were so named because together they consist of 48 hairpin turns. The road's winding design, providing stunning panoramic views, is very curvy and fun for a leisurely ride, so it pays to take it slow. Exercise extreme caution when passing on-coming traffic, over-taking and around corners. Drive with your headlights on at all times as it is easier for oncoming vehicles to see you.
Today, the older road is only open to downward traffic and includes a pit stop from where you can see two waterfalls. The newer road, meanwhile, is only open to upward traffic as far as the Akechidaira Plateau near the top of the road. People started calling the slope Iroha-zaka in the early Showa era. Ancient Japanese alphabet consisted of 48 letters, and the number of curve is 48. Therefore, tourist guides started calling the slope Iroha-zaka. Today, the number of curve is 30 because the road was improved in 1954.The two roads were respectively built in 1954 and 1965 as some of Japan's first toll roads, but were later turned toll free.
This road has been heralded as one of the most spectaculars roads in the world by the dangerousroads.org users. Today's First Iroha-zaka was made in that time. In addition, the Second Iroha-zaka (Up only) was made to adjust more traffic. The number of curves increased up to 50, but 2 curves were decreased in order to match to the 48 letters.