Ichirizuka were built by Ieyasu Tokugawa in 1604 to improve the roads throughout the country, and were placed every 1 ri (about 4 km) along the roads. They were placed at every 1 ri (about 4 km) along the highway and served as a guide for travelers and a resting place, but they disappeared after the modern era due to deterioration caused by weather and changes in the transportation system. Shimura-isurizuka was the third such mound to be built along the Nakasendo route, and is one of the most valuable historical sites in Japan, with two remaining in pairs.