Yoshimi-Hyakuana is composed of hundreds of ancient tomb dugs into the side of a hill. These were made between late 6th century and late 7th century.. It was designated as a historical site at 1923.Though ancient tomb dug into the side of a hill is made by drilling slope, its main construction is similar to that of stone hut. Yoshimi-Hyakuana whole area is covered by tuffaceous sandstone. Tuffaceous sandstone is easy to dig. That is the reason why ancient tomb dugs into the side of a hill exist here. In 1870s and 1880s, excavation was carried out but the results are some excavated article only. The number of ancient tomb dugs is 219.