Forty-eight curves, and you are up. Irohazaka is the road linking central Nikko to Lake Chuzenji and the highlands beyond, and it is really two roads: the first runs downhill only, the second uphill only. Between them they hold forty-eight hairpins, which is where the name comes from—iroha, the old ordering of the Japanese syllabary, forty-eight characters long. Each curve carries a sign with its character, in sequence, so you can read your position off the roadside as you climb.

The climb gains about 440 metres. Partway up the second road is Akechidaira, where a deck looks back across the valley and you can pick out the first Irohazaka threading the far slope. Colour reaches the top in late October and works downward from there, which means the same road shows you three different weeks of autumn at three different heights on a single afternoon.

The road was cut in stages through the twentieth century, replacing a pilgrimage path to the shrines and the lake above. The whole of it sits inside Nikko National Park.

The real variable is not weather but traffic. A drive that takes twenty minutes in June can take two or three hours in season; over a long weekend the queue has reached six. So the question this place asks is not where to stand but when to move—before mid-morning, or late enough that the day trippers have started down. Go at the wrong hour and you will still see it. You will simply see it slowly.