There are carp swimming in the channel beside the road. Tonomachi-dōri in Tsuwano runs between white walls and samurai gates, with an open water channel along one side in which large carp are kept, so there is colour moving at ankle height the whole way along. A church stands on the same street, which produces an unusual juxtaposition: a Western building in the middle of a samurai quarter, neither of them apologising for the other.

Tsuwano was designated an Important Preservation District in August 2013. From the same street you can walk to the path up the castle hill or to the approach to the Inari shrine, so the town's three different kinds of destination are all within a few minutes of one another. Masuda is about forty minutes away by car and Yamaguchi about an hour. The population is in the seven thousands, gathered in a basin between hills. The carp are said to have been kept originally as a reserve against famine; now they also serve as a visible indicator of how clean the water is.

Fish in a channel make people less willing to foul it. Keeping livestock where everyone can see it is a more reliable arrangement than a rota for cleaning, because the consequence of neglect is immediate and public — so the carp are simultaneously scenery and a piece of municipal regulation. They were not released for visitors to photograph. They have become the thing visitors photograph, which is a different matter entirely, and the town has felt no particular need to correct the impression. The channel is cleaner for the attention, and the fish are unaffected by being admired.