Tonomachi Street in Tsuwano, Shimane Prefecture, is the main road in a preservation area of traditional structures. The waterways flowing along the street and the namako plastered walls of the buildings have become a symbol of Tsuwano. Brightly-colored koi carp can be seen swimming through the waterways, and from late May to mid-June the area is garnished with white and purple iris blossoms. This street is a place that was once home to traditional mansions, but a lot of historical sites are concentrated in the surroundings as well; nearby, one can find a Catholic church, the Yorokan clan school ruins, county office remains, the front gate of the former residences of the Tago clan, who were the chief retainers of the Tsuwano Domain, and more. The whole area retains the air of the town of the past, so history buffs should make sure not to miss it.