There is little evidence of human activity in the early part of the Jōmon period in the Kumamoto Prefecture, because of volcanic activity about 7300 years ago by the Kikai Caldera in Kagoshima Prefecture. The Goryo midden and Kurohashi midden date to the middle age of the Jōmon period. Later, 13 middens in Kumamoto were situated at the height of 5 meters above sea level. In Souhata midden, stored acorns were found. Fish hooks made of stone were found in Amakusa. A peculiar style of earthenware called kokushokukenmadoki was developed according to the development of living styles. Burned rice corns and barley corns were found in a dugout (shelter) dwelling in Uenobaru midden in Kumamoto City. 770 Archaeological sites were found in the Jōmon period in Kumamoto Prefecture, including Kannabe midden, Kumamoto in which Dogūs and ground stones were found.