Iroha-zaka Road
A scenic highway connects the city of Nikkō with the Oku-Nikkō area. It is divided into two one-way roads, Iroha-zaka No. 1 and No. 2, which traverse the 440-meter difference in elevation between the Umagaeshi area at the bottom and Lake Chūzenji at the top through a series of switchbacks.
“Iroha” is the name of a poem that uses each of the 48 characters of the Japanese syllabary exactly once. The poem appears, one character at a time, on signs at each bend in the road. The first 20 characters appear on the ascending route (No. 2), while the descent (No. 1) starts from the 21st character and finishes the poem.
Iroha-zaka No. 1, on the north side of Kegon Gorge, is 6.5 kilometers long.
Iroha-zaka No. 2, on the south side of the gorge, is 9.5 kilometers long.