The Nagatoro tourism association puts the peak here in the middle to late part of November, while noting that the colouring season itself is longer at both ends. The peak is the useful number; the season is the reason people keep coming back.

Nagatoro is not one viewpoint but several, spread along a stretch of the Arakawa, and they are close enough together to be walked between. Iwadatami — flat shelves of rock forming the riverbank — reads best from one of the boats that run the river, because from water level you look up at the bank rather than down at it. Across from it stands the cliff known as the Chichibu Sekiheki, with the trees around the shelves turning against it.

The Kaneishi Suikankyo bridge gives the opposite kind of view: from the deck you can turn through the whole valley in one movement. For height, a ropeway climbs Mount Hodo, from which the colour reads as an extent rather than as individual trees. Height changes the subject.

Tsuki-no-ishi Momiji Park is lit in the evening, which makes it the one place here worth walking twice, once in daylight and once after dark. Weekends in the peak fortnight are busy and the car parks near the station fill first; the trains from Kumagaya and Chichibu are the easier way in.