This is a road you look at rather than a mountain you climb. The Bandai-Azuma Skyline runs about 29 kilometres from Takayu Onsen to the Tsuchiyu pass, threading the ridgeline of the Azuma range at heights around 1,600 metres. It opens in late April and closes in mid-November for the winter, so the season for driving it is short and the autumn part of that season is shorter still.

Partway along is Jododaira, a plateau of marsh and car park at the foot of Azuma-Kofuji, a small symmetrical cone you can walk up to the crater rim in about twenty minutes. The prefecture's tourism body gives late September to mid-October as the usual peak. Altitude does that—the colour here is finished while the lowlands are still warm.

The road has been promoted for decades under the name Azuma Hakkei, the eight views of Azuma, and it lies inside Bandai-Asahi National Park.

What surprises people is what the colour sits on. This is not a forest road. Much of the upper section is volcanic ground—grey rock, sulphur, bare slopes with low scrub holding on—and the reds and yellows are spread thin across that surface rather than piled into a canopy. It reads as geology first and autumn second. Stop the car. It is a better view standing still than through glass.