Kanazawa was a castle town of the Kaga Clan governed by the Maeda family until 1868 (about 280 years) after Maeda Toshiie moved to Kanazawa Castle in 1583. The residences of two of the eight chief retainers of the Kaga Clan were located in the Naga-machi area, where top- and middle-class samurais (members of a feudal powerful military class) lived. With the arrival of the modern age, the appearances of the houses changed. The alleys and the mud walls of nagayamon gates (row house gates), however, still maintain the sight of the old days. A mud wall is made with stones and mud put into a mold and hardened. The roof is covered with thin wooden plates. Although mud walls that passed more than 100 years remain, most of the mud walls in the area were restored ones. There is a large quantity of snow in winter in Kanazawa. In order to prevent damage to the mud walls at the time of the spring thaw, straw mats called "komo" is used to protect the mud walls every year from early in December to middle of March. The Onosho canal, which flows around the area, was the oldest canal of Kanazawa, which was an important waterway that carried goods from the harbor to the castle town.