Semboku's city tourism pages give the usual peak here as mid-October to early November. Dakigaeri is a narrow gorge on the middle Tamagawa, ten kilometres of it, running between Lake Tazawa and the samurai streets of Kakunodate. The name is literal and old. Before the path was cut, two people meeting on the ledge had to hold each other and turn, one passing the other back the way they had come.

The walking path now follows the water, and a suspension bridge called Kami-no-Iwahashi crosses it near the entrance. From the middle of that bridge you look straight down the length of the gorge. Further in is the Mikaeri falls, a name meaning roughly the falls you keep turning back to look at. Allow forty minutes each way, less if you only want the bridge.

Two practical points, both from the city rather than a guidebook. Bears are active here, and the path has five metal pipes installed for walkers to strike so that animals hear people coming. The city asks that nobody walk the gorge alone. Sections also close for repair work, and the upper walkway shuts for winter before the end of November.

By car it is fifteen minutes from JR Kakunodate station and twenty from Tazawako. During the autumn festival, which opens in the middle of October, reservation-only buses and shared taxis serve the gorge from both stations, and the car parks fill early on clear weekends. Check the city's tourism page the week you go.