Shimane's prefectural tourism site puts the colour here between late October and the middle of November. That is early for a gorge, and it is the first thing worth knowing about Tachikuekyo.

The rock does the work. For roughly two kilometres along the Kando river, stone pillars and cliffs stand on both banks — Tengu-iwa, Byobu-iwa, Rosoku-iwa, Eboshi-iwa, each named for what it resembles. Trees have taken hold in the seams and on the ledges, so when they turn, the grey columns are edged in red rather than hidden by it. The effect depends on where you stand. Walk the riverside path and the order of the pillars keeps shifting.

The gorge changes through the year: mountain cherry in spring, dense green in summer, snow in winter. Only in this one month do the rock and the colour sit in the same frame. It is also unusually close to a city for a place that looks like this, about twenty minutes by car from central Izumo, which makes it an easy half day rather than an expedition.

Buses run from Izumoshi station on the Sanin main line and take thirty minutes; get off at Tachikuekyo. There is no admission charge. Come on a weekday morning if you can, when the light reaches down into the gorge and the path is quiet.